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The effect of non­pharmacological sleep 
interventions on depression symptoms: a 
meta­analysis of randomised controlled 
trials 
Article 

Accepted Version 

Gee, B., Orchard, F., Clarke, E., Joy, A., Clarke, T. and 
Reynolds, S. (2019) The effect of non­pharmacological sleep 
interventions on depression symptoms: a meta­analysis of 
randomised controlled trials. Sleep Medicine Reviews, 43. pp. 
118­128. ISSN 1532­2955 doi: 
https://doi.org/10.1016/j.smrv.2018.09.004 Available at 
http://centaur.reading.ac.uk/79287/ 

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RUNNING

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The Effect of Non-Pharmacological Sleep Interventions on Depression Symptoms: A

Meta-Analysis of Randomised Controlled Trials

Brioney Gee1,2, Faith Orchard3, Emmet Clarke1, Ansu Joy1, Tim Clarke1,2, Shirley Reynolds3

1Norfolk and Suffolk NHS Foundation Trust, UK

2Norwich Medical School, University of East Anglia, UK

3School of Psychology and Clinical Language Sciences, University of Reading, UK

Corresponding Author:

Dr Brioney Gee

Norfolk and Suffolk NHS Foundation Trust

80 St Stephens Road, Norwich, UK.

NR1 3RE

Email: brioney.gee@nsft.nhs.uk Tel: +44 (0)1603 201455

Acknowledgments

We would like to thank Drs Matthew Blake, Kenneth Lichstein and Ron Postuma for sharing

additional data for inclusion in the meta-analysis and the staff of Norfolk and Suffolk NHS

Foundation Trust Frank Curtis Library for their assistance in accessing articles. This review

was not supported by any specific funding. We have no conflicts of interest to declare.

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Summary

Poor sleep is a significant risk factor for depression across the lifespan and sleep

problems

have been hypothesised to contribute to the onset and maintenance of depression symptoms.

However, sleep problems are usually not a direct target of interventions for depression. A

range of non-pharmacological treatments can reduce sleep problems but it is unclear whether

these interventions also reduce other depression symptoms. The aim of this review was to

examine whether non-pharmacological interventions for sleep problems are effective in

reducing symptoms of depression. We carried out a systematic search for randomised

controlled trials of non-pharmacological sleep interventions that measured depression

symptoms as an outcome. Forty-nine trials (n=5908) were included in a random effects meta-

analysis. The pooled standardised mean difference for depression symptoms after treatment

for sleep problems was -0.45 (95% CI: -0.55,-0.36). The size of the effect on depression

symptoms was moderated by the size of the effect on subjective sleep quality. In studies of

participants with mental health problems, sleep interventions had a large effect on depression

symptoms (d=-0.81, 95% CI: -1.13,-0.49). The findings indicate that non-pharmacological

sleep interventions are effective in reducing the severity of depression, particularly in clinical

populations. This suggests that non-pharmacological sleep interventions could be offered as a

treatment for depression, potentially improving access to treatment.

Keywords: depression; mood; sleep; insomnia; intervention; treatment; meta-analysis

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Glossary

Cognitive behavioural therapy for insomnia: A multi-component psychological intervention

comprising a range of strategies designed to target the behavioural and cognitive

underpinnings of insomnia.

Forest plot: Graphical representation of the results of a meta-analysis.

Funnel plot: Used to detect bias in trials included in a meta-analysis. Publication bias will

result in asymmetry in the plot.

Heterogeneity: Variability in observed effect sizes that is greater than would be expected by

chance alone.

Meta-regression: A statistical technique that allows the association between continuous, as

well as categorical, study characteristics and the intervention effects observed to be

investigated.

Paradoxical intention: Instructing the client to stop trying to fall asleep and instead stay

awake for as long as possible in order to lessen anxiety about falling asleep.

Rosenthal’s failsafe N: The number of additional studies in which the intervention effect was

zero that would need to be included in a meta-analysis to increase the P value to above 0.05.

Sleep restriction therapy: Limiting the time spent in bed to the actual time spent sleeping in

order to increase sleep efficiency.

Stimulus control therapy: Providing the client with instructions designed to re-associate the

bed/bedroom with sleep.

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Introduction

Depression is a common mental health problem, with a lifetime prevalence of approximately

15% in high income countries [1]. It is among the leading causes of disability globally [2],

but only a small minority of individuals experiencing depression receive adequate treatment

[3]. More than 65% of adults with major depressive disorder report sleep difficulties [4,5],

including difficulty falling asleep, frequent awakenings during the night, early morning

awakening and non-restorative sleep [6], and around 40% report sleep disturbance severe

enough to warrant a diagnosis of insomnia [7]. Among adolescents with depression, recent

research indicates that up to 90% present with disturbed sleep [8,9]. In both children and

adults, those who experience sleep problems present with more severe depression than

depressed individuals without sleep problems [10,11].

Depression has often been conceptualised as a cause of sleep problems [12], reflected in the

inclusion of sleep disturbance in the diagnostic criteria for depressive disorders in both

commonly used diagnostic manuals (DSM-5 [13] and ICD-10 [14]). However, sleep

problems often predate the onset of depression [15,16], and are among the most commonly

reported residual symptoms after the remission of a depressive disorder [17]. Thus it has been

suggested that, rather than sleep problems being a symptom or consequence of depression,

that depression and sleep disorders may constitute separate syndromes that co-occur as a

result of shared causal pathways [18].

Longitudinal research suggests a bidirectional relationship between depression and sleep,

with sleep disturbances predicting later depressive episodes as well as vice versa [19]. In a

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meta-analysis of longitudinal studies, the risk of non-depressed individuals with

insomnia

subsequently developing depression was found to be twice that of people without sleep

difficulties [20]. Studies examining the prospective role of sleep in the development of

depression have found sleep problems to be a risk factor for subsequent depression across the

lifespan, from adolescence [21] through to older adulthood [22].

Further, there is some evidence to support the hypothesis that poor sleep might play a causal

role in the onset and maintenance of depression symptoms [23,24]. In experimental and

quasi-experimental studies, sleep deprivation has been found to increase negative mood [23],

decrease positive emotional responses to goal-enhancing events [25] and bring about poorer

memory for positively valenced words [26]. In addition, healthy adult volunteers subjected to

six days of sleep curtailment have been found to show electroencephalography abnormalities

and endocrine disturbances usually observed in depression [18]. In adolescents, even modest

sleep restriction over five nights has been found to result in worsened mood, increased

irritability and decreased ability to regulate negative emotions [27].

Given the hypothesis that poor sleep might contribute to the onset and maintenance of

depression, it is plausible that treatments that are successful in improving sleep might also

lead to reductions in symptoms of depression. Pharmacological sleep treatments have been

found to produce short-lived improvements in sleep but are not recommended for longer-term

sleep problems due to poor efficacy [28] and concerns about dependence and other adverse

effects [29].

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Non-pharmacological interventions are effective in improving sleep, both in individuals with

insomnia [30,31], and in those with sleep problems in the context of medical and psychiatric

disorders [32–34]. Insomnia is the most common sleep complaint, both in individuals with

depression [5,11] and in the general population [34]. A range of non-pharmacological

interventions have been found to be effective treatments for insomnia, including stimulus

control therapy, relaxation training, sleep restriction therapy, biofeedback, paradoxical

intention and multicomponent cognitive behavioural therapy for insomnia (CBT-I) [35].

Depression symptoms are often measured as a secondary outcome in trials of non-

pharmacological interventions designed to improve sleep. A number of previous reviews

have included analyses of the effect of interventions targeting sleep problems on depression

symptoms. The results of previous meta-analyses suggest that both internet-delivered [36]

and group-based [37] CBT-I have small but significant effects on depression symptoms,

despite these symptoms not being specifically targeted.

However, a recent network meta-analysis of behavioural and cognitive behavioural

interventions for adults with insomnia [38] found that only individual, face-to-face CBT-I

had a significant effect on depression symptoms when compared to a placebo condition.

Studies were included in this analysis if the trial intervention incorporated sleep restriction,

and depression was measured using a standardised measure. The authors grouped the CBT-I

interventions trialled into six classes according to their treatment components and delivery

mode, and compared each class of intervention to placebo conditions (pills or behavioural

placebo). Significant moderate-sized mean effects were found for individual CBT-I, but no

significant effects were found for other treatment classes. However, the conclusions that

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could be drawn were limited by significant heterogeneity that was not explained by the

clinical, demographic or methodological characteristics examined, which included age, sex,

whether participants with comorbidities were excluded, and risk of bias.

One possible source of heterogeneity in the effect of sleep interventions on depression is

variation in the size of effect on the sleep symptoms directly targeted. The authors of a recent

review of CBT-I in adults with co-morbid major depressive disorder [39] suggest that

improvement in depression following CBT-I may be mediated by improvement in insomnia

symptoms. There are plausible mechanisms through which improvements in sleep might lead

to improvements in depression symptoms. These include the impact of improved sleep on

quality of life, emotion regulation and cognitive functioning [40,41], as well as reductions in

neurobiological abnormalities common to both mood and sleep disturbances [42]. However,

there are also a range of non-specific factors that might account for the effect of sleep-

interventions on depression, for instance increased motivation or hope as a result of

developing a therapeutic relationship or participation in a therapeutic process [43]. As such,

the extent to which improvements in depression symptoms are accounted for by improved

sleep warrants investigation.

The aim of the current review was to identify and synthesise the results of all randomised

controlled trials of non-pharmacological interventions designed to improve sleep that

reported depression symptoms as an outcome. Eligible interventions were designed to

improve the amount, quality or timing of sleep, including but not limited to interventions for

insomnia. The review was not restricted to a particular intervention or client group, and the

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impact of the age of trial participants and presence or absence of mental health comorbidities

was examined.

A secondary goal was to examine whether improvements in symptoms of depression were

moderated by improvements in subjective sleep quality in order to assess whether

heterogeneity in the effect of sleep interventions on depression can be explained by variation

in how effective the intervention is in improving perceived sleep quality. Better

understanding the impact of non-pharmacological sleep interventions on depression

symptoms will be important in enabling us to assess in which cases interventions targeting

sleep might be appropriately harnessed as treatment options for depression.

Methods

Search strategy

The review was conducted in accordance with guidance in the ‘preferred reporting items for

systematic reviews and meta-analyses’ (PRISMA) statement [44]. The protocol was

registered with the PROSPERO registry prior to implementation of the search strategy and

can be accessed at:

http://www.crd.york.ac.uk/PROSPERO/display_record.asp?ID=CRD42017054940.

The search strategy aimed to identify all eligible trials reported in the English language in a

peer-reviewed journal. Four electronic databases, PsycINFO, Medline, CINAHL and

CENTRAL, were searched from their inception until 1st May 2018. The following search

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terms were used: (sleep OR insomnia OR “sleep treatment” OR “sleep disorders”) AND

(intervention OR treatment OR therapy OR help OR hygiene OR support OR education)

AND (depressi* OR mood). Limiters were used to narrow the search to clinical trials and

English language publications. We also hand searched the reference lists of eligible articles

and key review papers to identify any eligible articles missed by the electronic search.

Eligibility Criteria

The inclusion criteria employed were as follows: (1) randomised controlled trial; (2) trial

intervention was a non-pharmacological intervention specifically designed to improve sleep

(amount, quality or timing); (3) trial included a control condition not designed to improve

sleep; (4) depression symptoms were measured (as either a primary or secondary outcome)

using a validated instrument; (5) the trial was reported in the English language in a peer

reviewed journal. Studies that met any of the following criteria were excluded: (1) the trial

intervention included a pharmacological component (including traditional/herbal remedies);

(2) all trial arms received an intervention designed to improve sleep (for instance, the only

control condition was a pharmacological sleep aid or sleep hygiene); (3) trial intervention

was designed to treat parasomnias, sleep apnoea or fatigue (as these are thought to have

causal factors distinct from other sleep problems).

Study selection

The titles and abstracts of all retrieved articles were screened by one reviewer (BG). A

subsample of 10% of articles (selected using a random number generator) was screened

independently by a second reviewer (AJ) to check that no potentially eligible articles were

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excluded. The full texts of all articles deemed potentially relevant were obtained and assessed

for eligibility against the inclusion/exclusion criteria by two reviewers independently (BG

and one of FO, EC, AJ, TC or SR). All disagreements regarding eligibility were discussed by

the two reviewers and, if consensus not reached, resolved by a third reviewer. Where multiple

publications describing the same trial were identified, only the article reporting on the larger

sample was included.

Data extraction and quality assessment

Data were extracted independently by two reviewers (BG and EC) and cross-checked to

ensure accuracy. The following information was recorded using a customised data extraction

spreadsheet: study characteristics (authors, title, year of publication), intervention type, age of

sample, psychiatric comorbidities, depression measure used, subjective sleep quality

measure

used, size of intervention and control groups, baseline and outcome data (at first time-point

post-intervention) for depression and sleep quality (means and standard deviations). Where

insufficient outcome data were reported for the study to be included in the meta-analysis, we

contacted corresponding authors to request this data. The methodological quality of included

studies was assessed by one reviewer (AJ) using the Cochrane collaboration’s risk of bias

tool [45]. For a random subsample of 10% of included studies, the risk of bias assessment

was independently verified by a second reviewer (BG) and discrepancies resolved through

discussion.

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Data synthesis

All eligible studies for which sufficient data on depression outcomes were reported or could

be obtained from the corresponding author were included in a random effects meta-analysis.

Review Manager Version 5.3 [46] was used to perform the meta-analysis. Standardised mean

differences of depression scores at post-intervention and their 95% confidence intervals were

calculated for each study, and weighted according to sample size via the random effects

model. Standardised mean differences greater than 0.8 were considered large, 0.5 moderate

and 0.2 small [47].

Where more than one non-pharmacological intervention designed to improve sleep was

included in the trial, data for the most intensive intervention was included in the meta-

analysis. The most intensive intervention was determined by consensus of two reviewers

based on the amount of face-to-face contact the intervention included (so that interventions

delivered in a self-help format were classed as less intensive than therapist-delivered

interventions). A random effects model was selected as we expected there would be

heterogeneity in study effect sizes because of diversity in their target populations and the

specific interventions trialled. Statistical heterogeneity was assessed using the Chi2 and I2

statistics. Significant heterogeneity is indicated by a Chi2 statistic greater than the degrees of

freedom and a p value<0.05; I2 values range from 0% to 100%, with higher values indicating

greater heterogeneity [48]. Publication bias was assessed via construction and visual

inspection of a funnel plot and by calculating Rosenthal’s failsafe N.

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Two planned subgroup analyses were carried out to investigate sources of heterogeneity. The

first divided the studies into those that recruited from populations who had sleep problems in

the context of mental health problems and those that recruited from populations without

clinical mental health problems. Studies were classified as recruiting from a population with

mental health problems if all participants either (a) meet standardised diagnostic criteria for at

least one functional mental disorder (determined via chart review or diagnostic interview) or

(b) scored above the clinical threshold on a validated measure of mental health

symptomatology. The second planned subgroup analysis divided the studies according to the

age range of participants: children/adolescents (aged up to 19), adults (aged 18+), older adults

(aged 50+). Additionally, a post-hoc subgroup analysis was conducted to investigate the

impact of the depression measure employed on the effect size detected. Only trials that

measured depression using an instrument employed by at least two other trials were included

in this analysis.

Finally, a random effects meta-regression was carried out to assess whether the effect of an

intervention on depression symptoms was predicted by its effect on subjective sleep quality.

This was achieved by calculating effect sizes (standardised mean difference) for all studies

that reported subjective sleep quality post-intervention and entering these as covariates in a

meta-regression using Field and Gillett’s SPSS syntax files [49].

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Results

Study selection

The study selection process is illustrated in Figure 1. Sixty-one papers were identified that

met the inclusion criteria, however three were secondary analyses of already included trials

and we were unable to obtain sufficient depression data for inclusion in the meta-analysis

from the published report or by contacting the corresponding author for nine studies.

Therefore data from 49 articles are included in the meta-analysis.

[Inset Figure 1]

Characteristics of included studies

Characteristics of the 49 trials included in the meta-analysis are summarised in Table 1. The

meta-analysis included data on 5908 participants, of whom 2731 were randomised to receive

the trial sleep intervention. The included trials were all of psychological interventions. The

majority (39 out of 48 studies) were described by the study authors as CBT-I or CBT-

informed interventions. Sixteen studies trialled interventions delivered in a self-help format,

online or via a mobile application. The remaining trials were of face-to-face interventions, 27

delivered individually and five delivered in a group format. Control conditions included

active interventions not specifically targeting sleep (e.g. dietary advice, exercise

programmes), and passive controls, such as medical treatment as usual and waitlist.

Most participants were adults; only four studies included young people aged under 18

(n=292) and none included children under 11 years. Many of the studies recruited participants

with physical health problems (e.g. chronic pain, heart failure, cancer), for whom sleep was a

secondary or additional problem. Twenty studies recruited participants with sleep problems

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and no other comorbidity. Half of the included studies excluded participants deemed to have

clinical levels of depression symptoms (defined either as meeting diagnostic criteria for a

depressive disorder or scoring above a specified cut-off on a measure of depression

symptoms). A wide range of measures of depression symptoms were used and included

widely used self-report questionnaires, as well as observer rating scales (e.g. the Hamilton

rating scale for depression). Subjective sleep quality (including self-reported insomnia

severity) was measured by 43 of the 49 included studies. The trials were conducted in high

and upper-middle income countries across four continents (Europe, North America, Asia and

Australasia).

[Insert Table 1]

Risk of bias

The Cochrane collaboration’s risk of bias tool was used to assess the quality of the included

studies and a risk of bias summary graph produced (Figure 2). The majority of studies were

judged to be of high quality, though few studies were able to blind participants and research

personnel, and most papers included insufficient information to be able to determine the risk

of bias due to poor allocation concealment or selective reporting. The measures of depression

used in the studies had sound psychometric properties, and where young people under 18

were included, had been validated for use with adolescents.

[Insert Figure 2]

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Meta-analysis of effect on depression symptoms at post-treatment

The results of the random effects meta-analysis are illustrated in Figure 3. There was a small

to moderate effect of non-pharmacological sleep interventions in reducing depression

symptoms in comparison to control conditions not designed to improve sleep (standardised

mean difference = -0.45, 95% CI -0.55, -0.36, p<0.001, k=49). The statistical heterogeneity

in effect sizes among studies was moderate (I2=56%, χ2=108.8, df=48, p<0.001).

[Inset Figure 3]

Subgroup analyses and meta-regression

Comorbid mental health difficulties

Seven of the included studies recruited from participants with clinical mental health problems

(typically anxiety, depression and PTSD) in addition to sleep difficulties. The subgroup

analyses showed that the pooled effect on depression symptoms for these seven studies was

large (standardised mean difference = -0.81, 95% CI -1.13, -0.49, p<0.001, k=7) and the

statistical heterogeneity among these studies was small (I2=27%, χ2=8.19, df=6, p=0.22). In

comparison, the subgroup of studies that recruited participants without clinical mental health

difficulties (k=42) found a small effect on depression symptoms (standardised mean

difference = -0.41, 95% CI -0.51, -0.31, p<0.001) and these effect sizes were more

heterogeneous (I2=56%, χ2=93.45, df=41, p<0.001).

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Adolescents, adults and older adults

The majority of included studies recruited adults of all ages. Four of the studies recruited

adolescents (all participants under the age of 20) and three recruited only adults over the age

of 50. The four trials in adolescents had the smallest pooled effect on depression

symptoms

(standardised mean difference = -0.27, 95% CI -0.50, -0.04, p=0.02, k=4), with no statistical

heterogeneity (I2=0%, χ2=1.99, df=3, p=0.57). The pooled effect on depression symptoms for

the studies with adult participants was small to moderate (standardised mean difference = –

0.46, 95% CI -0.57, -0.36, p<0.001, k=42) with moderate heterogeneity (I2=59%, χ2=100.75,

df=41, p<0.001). The three studies that recruited adults over the age of 50 had the largest

pooled effect size but wide confidence intervals (standardised mean difference = -0.60, 95%

CI -1.12, -0.08, p=0.02, k=3) and moderate heterogeneity (I2=47%, χ2=3.76, df=2, p=0.15).

Depression measure

The centre for epidemiological studies depression scale (CESD) was the most commonly

used depression measure in the included studies (k=11), followed by the Beck depression

inventory (BDI) (k=10), hospital anxiety and depression scale (HADS) (k=8), nine item

patient health questionnaire (PHQ-9) (k=4) and the Beck depression inventory version II

(BDI-II) (k=3). All other measures were employed in less than three of the included trials.

The standardised mean difference was largest for trials that measured depression using the

PHQ-9 (-0.70, 95% CI -1.00, -0.41, p<0.001), followed by the BDI (-0.56, 95% CI -0.76, -

0.36, p<0.001), the CESD (-0.45 95% CIs -0.67, -0.24, p<0.001), and the HADS (-0.34, 95%

CIs -0.57, -0.11, p=0.003). It was smallest in trials that used the BDI-II (-0.12, 95% CIs –

0.36, 0.13, p=0.34).

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Effect on subjective sleep quality

The standardised mean difference for subjective sleep quality at post-intervention could be

calculated in the case of 40 of the 49 included studies. There was a positive linear

relationship between the standardised mean difference of the sleep interventions on

depression symptoms and the standardised mean difference for subjective sleep quality. The

meta-regression revealed that the size of the effect on subjective sleep quality was a

significant continuous moderator of the effect on depression symptoms (β=0.447, 95% CI

0.29, 0.60, p<0.001). The residual variation was non-significant (χ2=41.89, p=0.306)

suggesting the statistical heterogeneity in the size of the effect of the studied sleep

interventions on depression symptoms can be explained by variation in their effect on

subjective sleep quality.

Publication bias

Inspection of the funnel plot suggested that effect sizes might be slightly inflated in some

smaller studies, with one small study a notable outlier. However, this might be explained by

clinical diversity among the populations studied since trials that recruited participants with

sleep problems in the context of mental health problems tended to find larger effect sizes and

to have smaller samples than the studies that recruited participants without clinical mental

health problems. Rosenthal’s failsafe N was 3593.46, indicating that 3593 studies with zero

effect sizes would be needed to nullify the pooled effect.

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Discussion

We reviewed the evidence of the effect of non-pharmacological interventions designed to

improve sleep on the severity of depression symptoms. The meta-analysis showed that non-

pharmacological sleep interventions reduce the severity of depression symptoms immediately

post-intervention, and this finding was robust to the possibility of publication bias. The

pooled effect on depression severity was in the small to moderate range. This is comparable

to the effect size of targeted non-pharmacological interventions for depression delivered in

primary care [50,51] and to non-pharmacological interventions for depression that is

comorbid with physical health problems [52–54]. The effect is, however, somewhat smaller

than the effect sizes of non-pharmacological interventions for depression delivered to

individuals with major depression disorder [55].

As would be expected given that most eligible trials were of CBT-I, or CBT-informed

interventions for insomnia, the effect on depression symptoms we identified is comparable to

the effects on depression symptoms reported in previous meta-analyses of CBT-I [36–38].

The size of reduction in depression symptoms is also similar to the effect on anxiety

symptoms in a meta-analysis of CBT-I trials [56], suggesting that non-pharmacological sleep

interventions are similarly effective in reducing both depression and anxiety.

Whilst the pooled effect of non-pharmacological sleep interventions on depression symptoms

is small to moderate, there was considerable heterogeneity in the size of effects observed.

This heterogeneity is in line with previous research [38] and unsurprising given the variation

in the participants recruited and the type of interventions trialled by the included studies. For

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participants with mental health problems, sleep interventions had a large effect on symptoms

of depression. Such interventions have previously been found to have large effects on sleep

symptoms in individuals with mental health problems [57]. Therefore, sleep interventions

might be of particular benefit to this group.

The pooled effect size for studies that recruited children and adolescents was small compared

to the effect sizes for those studies that recruited adults and older adults. These relatively

modest effects on depression symptoms are in line with the small effect sizes that have been

found in studies of non-pharmacological therapies directly targeting depression in children

and young people [58,59]. However, none of the studies included in this review investigated

the effect of non-pharmacological sleep interventions on children or adolescents with clinical

level mental health difficulties, including depression, for whom sleep difficulties are both

common and distressing [8,9]. Given the effect of sleep interventions on depression

symptoms was larger in studies that recruited participants with sleep problems in the context

of mental health problems, the small effect on depression in studies of children and

adolescents might be partially accounted for by the lack of trials including young people with

clinical-level mental health problems. Therefore, the potential effects of sleep interventions

for depressed children and adolescents warrants further evaluation.

There was a strong association between the change in subjective sleep quality brought about

by an intervention and its effect on depression symptoms. The statistical heterogeneity in the

effect sizes for depression symptoms was nullified by the introduction of the effect size for

subjective sleep quality as a covariate in the random effects meta-regression, indicating that

the heterogeneity on the effect of the interventions on depression can be explained by

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heterogeneity in their effect on subjective sleep quality. This might support the contention

that changes in the severity of depression symptoms were brought about by changes in

subjective sleep quality.

However, it is also possible that the observed relationship between effects on depression

symptoms and subjective sleep quality is a consequence of non-specific features of the

intervention or study context impacting on both sleep and depression symptoms

independently. Further research is needed to fully understand the nature of the relationship

between the effect of sleep interventions on sleep and their effect on depression. Studies

incorporating objective measurement of sleep variables in addition to self-reported sleep

quality would potentially be informative.

Clinical implications

Currently, only a small minority of individuals experiencing depression receive adequate

treatment [3]. The stigma associated with mental health problems has been identified as an

important barrier to help-seeking and treatment adherence [60]. The effectiveness of non-

pharmacological sleep interventions on depression symptoms suggests that the use of non-

pharmacological interventions that target sleep (and not mental health difficulties) may offer

a relatively low stigma means of reducing depression symptoms in individuals who have both

sleep and mental health difficulties. Offering sleep interventions as a treatment option for

those who report depression symptoms might also be particularly useful for individuals

reluctant to engage in a targeted treatment for depression.

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21

Non-pharmacological sleep interventions can be successfully delivered in a variety of

relatively low-cost formats [28], therefore providing these as a treatment option for people

with depression has the potential to be cost-effective. However, caution should be exercised

in offering non-pharmacological sleep interventions as a standalone intervention for

depression symptoms; residual depression symptoms should be monitored and additional

interventions offered as necessary.

Limitations

A limitation of the current review is that, because diagnostic criteria for depression include

sleep problems as a symptom, measures of depression typically incorporate one or more

items assessing sleep symptoms. Since these items account for only a small proportion of the

total scale score, it is unlikely that changes on these items alone after treatment for sleep

problems could account for the size of the effects observed. However, lack of item level data

meant that it was not possible to isolate the effect of the interventions trialled on non-sleep

depression symptoms. Future trials should use depression measures that do not include items

assessing sleep symptoms or report item-level data to enable the effect of sleep interventions

on non-sleep depression symptoms to be investigated.

A further consideration in interpreting the results of this meta-analysis is that many studies

excluded people who reported elevated symptoms of depression or a history of major

depression. Thus, while we cannot be certain what effect this had on the pooled effect size, it

is possible that relatively low levels of depression before treatment for sleep problems

reduced the overall effect of treatment on depression symptoms. We were also unable to

RUNNING HEAD: EFFECT OF NON-PHARMACOLOGICAL SLEEP INTERVENTIONS ON DEPRESSION SYMPTOMS

22

assess whether participants in the included trials were offered treatment for depression or

provided with mood management techniques before or after their participation in the sleep

interventions trialled as this was not consistently reported.

The meta-analysis only included trials that reported adequate data on depression symptoms at

post-treatment. We could not include nine trials identified as eligible for inclusion in the

meta-analysis as we were unable to obtain sufficient data on depression outcome to calculate

the standardised mean difference. Also, we focused on outcomes immediately post-

intervention so are unable to comment on the longevity of the effects on depression observed.

Further, we only included trials that measured depression symptoms as an outcome. It is

possible that trials of non-pharmacological sleep interventions that did not measure

depression symptoms as an outcome might have differed from those that did in some fashion

that would impact the size of the effect obtained.

Conclusions

Non-pharmacological interventions designed to improve sleep have a positive impact on

depression symptoms. The size of the effect on depression is moderated by the effect on

subjective sleep quality and is largest for participants experiencing sleep problems in the

context of mental health difficulties. Further research investigating the mechanisms by which

sleep interventions impact depression symptoms is warranted.

RUNNING HEAD: EFFECT OF NON-PHARMACOLOGICAL SLEEP INTERVENTIONS ON DEPRESSION SYMPTOMS

23

Practice points

1. Available randomised controlled trial evidence indicates that non-pharmacological

interventions designed to improve sleep have a small to moderate effect on depression

symptoms when these are measured as a secondary outcome.

2. The size of the effect on depression symptoms is moderated by the effect of the

intervention on subjective sleep quality.

3. The effect on depression symptoms appears to be larger in adult than in children and

adolescents but this may be an artefact of the participants who were recruited.

4. We found evidence of a large effect for studies that recruited participants experiencing

sleep problems in the context of mental health difficulties. Offering non-

pharmacological sleep interventions to users of mental health services who are

experiencing concomitant mood and sleep problems may lead to significant

improvements in depression symptoms as well as sleep quality.

Research agenda

1. Future trials of sleep interventions should measure depression symptoms as an

outcome and report this data at item level where the depression instrument used

includes an item(s) assessing sleep problems.

2. Future studies should investigate the mechanisms through which sleep interventions

lead to improvements in depression symptoms.

3. The effect of sleep interventions on depression in children and adolescents with

mental health problems should be trialled.

RUNNING HEAD: EFFECT OF NON-PHARMACOLOGICAL SLEEP INTERVENTIONS ON DEPRESSION SYMPTOMS

24

References

[1] Kessler RC, Bromet E. The epidemiology of depression across cultures. Annu Rev

Public Health 2013;34:119–38. doi:10.1146/annurev-publhealth-031912-114409.The.

[2] World Health Organisation. The Global Burden of Disease: 2004 update. 2008.

doi:10.1038/npp.2011.85.

[3] Thornicroft G, Chatterji S, Evans-Lacko S, Gruber M, Sampson N, Aguilar-Gaxiola S,

et al. Undertreatment of people with major depressive disorder in 21 countries. Br J

Psychiatry 2017;210:119–24. doi:10.1192/bjp.bp.116.188078.

[4] Yates WR, Mitchell J, Rush AJ, Trivedi MH, Wisniewski SR, Warden D, et al.

Clinical features of depressed outpatients with and without co-occurring general

medical conditions in STAR*D. Gen Hosp Psychiatry 2004;26:421–9.

doi:10.1016/j.genhosppsych.2004.06.008.

[5] Perlis ML, Giles DE, Buysse DJ, Thase ME, Tu X, Kupfer DJ. Which Depressive

Symptoms Are Related to Which Sleep Electroencephalographic Variables? Biol

Psychiatry 1997;42:904–13.

[6] *Benca RM, Peterson MJ. Insomnia and depression. Sleep Med 2008;9:3–9.

doi:10.1016/S1389-9457(08)70010-8.

[7] Stewart, Besset, Bebbington, Burgha, Lindesay, Jenkins, et al. Insomnia Comorbidity

and Impact and Hypotic Use by Age Group in a National Survey Population Aged 16

to 74 Years. Sleep 2006;29:1391–7.

[8] *Orchard F, Pass L, Marshall T, Reynolds S. Clinical characteristics of adolescents

referred for treatment of depressive disorders. Child Adolesc Ment Health 2017;22:61–

8. doi:10.1111/camh.12178.

[9] Goodyer IM, Reynolds S, Barrett B, Byford S, Dubicka B, Hill J, et al. Cognitive-

behavioural therapy and short-term psychoanalytic psychotherapy versus brief

psychosocial intervention in adolescents with unipolar major depression (IMPACT): A

multicentre, pragmatic, observer-blind, randomised controlled trial. Health Technol

Assess (Rockv) 2017;21:1–93. doi:10.3310/hta21120.

[10] Soehner A, Kaplan K, Harvey AG. Prevalence and clinical correlates of co-occuring

insomnia and hypersomnia symptoms in depression. J Affect Disord 2014;167:93–7.

[11] Liu X, Buysse DJ, Gentzler AL, Kiss E, Mayer L, Kapornai K, et al. Insomnia and

hypersomnia associated with depressive phenomenology and comorbidity in childhood

depression. Sleep 2007;30:83–90. doi:10.1093/sleep/30.1.83.

[12] Riemann D. Insomnia and comorbid psychiatric disorders. Sleep Med 2007;8:15–20.

doi:10.1016/j.sleep.2007.04.011.

[13] American Psychiatric Association. Diagnostic and statistical manual of mental

disorders. 5th Edition. American Psychiatric Association; 2013.

[14] World Health Organisation. The ICD-10 Classification of Mental and Behavioural

Disorders: Clinical descriptions and diagnostic guidelines 1992.

RUNNING HEAD: EFFECT OF NON-PHARMACOLOGICAL SLEEP INTERVENTIONS ON DEPRESSION SYMPTOMS

25

[15] Breslau N, Roth T, Rosenthal L, Andreski P. Sleep disturbance and psychiatric

disorders: A longitudinal epidemiological study of young adults. Biol Psychiatry

1996;39:411–8. doi:10.1016/0006-3223(95)00188-3.

[16] Roberts RE, Duong HT. Depression and insomnia among adolescents: A prospective

perspective. J Affect Disord 2013;148:66–71. doi:10.1016/j.jad.2012.11.049.

[17] Carney C, Segal Z, Edinger J, Krystal A. A comparison of rates of residual insomnia

symptoms following pharmacotherapy or cognitive-behavioral therapy for major

depressive disorder. J Clin Psychiatry 2007;68:254–60.

[18] Staner L. Comorbidity of insomnia and depression. Sleep Med Rev 2010;14:35–46.

doi:10.1016/j.smrv.2009.09.003.

[19] *Alvaro PK, Roberts RM, Harris JK. A Systematic Review Assessing Bidirectionality

between Sleep Disturbances, Anxiety, and Depression. Sleep 2013;36:1059–68.

doi:10.5665/sleep.2810.

[20] *Baglioni C, Battagliese G, Feige B, Spiegelhalder K, Nissen C, Voderholzer U, et al.

Insomnia as a predictor of depression: A meta-analytic evaluation of longitudinal

epidemiological studies. J Affect Disord 2011;135:10–9.

doi:10.1016/j.jad.2011.01.011.

[21] Lovato N, Gradisar M. A meta-analysis and model of the relationship between sleep

and depression in adolescents: Recommendations for future research and clinical

practice. Sleep Med Rev 2014;18:521–9. doi:10.1016/j.smrv.2014.03.006.

[22] Franzen PL, Buysse DJ. Sleep disturbances and depression: Risk relationships for

subsequent depression and therapeutic implications. Dialogues Clin Neurosci

2008;10:473–81.

[23] Harvey AG, Murray G, Chandler RA, Soehner A. Sleep Disturbance as

Transdiagnostic: Consideration of Neurobiological Mechanisms. Clin Psycohology

Rev 2012;31:225–35. doi:10.1016/j.cpr.2010.04.003.Sleep.

[24] Dolsen MR, Asarnow LD, Harvey AG. Insomnia as a transdiagnostic process in

psychiatric disorders. Curr Psychiatry Rep 2014;16:471. doi:10.1007/s11920-014-

0471-y.

[25] Zohar D, Tzischinsky O, Epstein R, Lavie P. The Effects Events of Sleep Loss a

Cognitive-Energy on Medical Model Residents’ Emotional Reactions to Work.

Sleep

2005;28:47–54. doi:10.1093/sleep/28.1.47.

[26] Walker MP, Stickgold R. Sleep, Memory, and Plasticity. Annu Rev Psychol

2006;57:139–66. doi:10.1146/annurev.psych.56.091103.070307.

[27] Baum KT, Desai A, Field J, Miller LE, Rausch J, Beebe DW. Sleep restriction worsens

mood and emotion regulation in adolescents. J Child Psychol Psychiatry 2014;55:180–

90. doi:10.1111/jcpp.12125.Sleep.

[28] Espie CA. “Stepped Care”: A Health Technology Solution for Delivering Cognitive

Behavioral Therapy as a First Line Insomnia Treatment. Sleep 2009;32:1549–58.

[29] National Institute for Health and Care Excellence. Guidance on the use of zaleplon,

RUNNING HEAD: EFFECT OF NON-PHARMACOLOGICAL SLEEP INTERVENTIONS ON DEPRESSION SYMPTOMS

26

zolpidem and zopiclone for the short-term management of insomnia. 2004.

[30] Edinger JD, Means MK. Cognitive–behavioral therapy for primary insomnia. Clin

Psychol Rev 2005;25:539–58. doi:https://doi.org/10.1016/j.cpr.2005.04.003.

[31] Morin CM, Bootzin RR, Buysse DJ, Edinger JD, Espie CA, Lichstein KL.

Psychological And Behavioral Treatment Of Insomnia: Update Of The Recent

Evidence (1998–2004). Sleep 2006;29:1398–414. doi:10.1093/sleep/29.11.1398.

[32] Riemann D, Perlis ML. The treatments of chronic insomnia: A review of

benzodiazepine receptor agonists and psychological and behavioral therapies. Sleep

Med Rev 2009;13:205–14. doi:10.1016/j.smrv.2008.06.001.

[33] Smith MT, Huang MI, Manber R. Cognitive behavior therapy for chronic insomnia

occurring within the context of medical and psychiatric disorders. Clin Psychol Rev

2005;25:559–92.

[34] *Geiger-Brown JM, Rogers VE, Liu W, Ludeman EM, Downton KD. Cognitive

behavioral therapy in persons with comorbid insomnia : A meta-analysis. Sleep Med

Rev 2015;23:54–67. doi:10.1016/j.smrv.2014.11.007.

[35] Morgenthaler T, Kramer M, Friedman L, Boehlecke B, Brown T, Coleman J, et al.

Practice parameters for the psychological and behavioral treatment of insomnia: an

update. An american academy of sleep medicine report. Sleep 2006;29:1415–9.

[36] *Ye Y, Zhang Y, Chen J, Liu J, Li X, Liu Y, et al. Internet-Based Cognitive

Behavioral Therapy for Insomnia (ICBT-i) Improves Comorbid Anxiety and

Depression—A Meta-Analysis of Randomized Controlled Trials. PLoS One

2015;10:e0142258. doi:10.1371/journal.pone.0142258.

[37] *Koffel EA, Koffel JB, Gehrman PR. A meta-analysis of group cognitive behavioral

therapy for insomnia. Sleep Med Rev 2015;19:6–16. doi:10.1016/j.smrv.2014.05.001.

[38] *Ballesio A, Aquino MRJ V., Feige B, Johann AF, Kyle SD, Spiegelhalder K, et al.

The effectiveness of behavioural and cognitive behavioural therapies for insomnia on

depressive and fatigue symptoms: A systematic review and network meta-analysis.

Sleep Med Rev 2018;37:114–29. doi:10.1016/j.smrv.2017.01.006.

[39] *Cunningham JEA, Shapiro CM. Cognitive Behavioural Therapy for Insomnia (CBT-

I) to treat depression: A systematic review. J Psychosom Res 2018;106:1–12.

doi:10.1016/j.jpsychores.2017.12.012.

[40] Harvey G. Insomnia, Psychiatric Disorders and the Transdiagnostic Disorders

Perspective. Assoc Psychol Sci 2008;17:299–303. doi:doi: 10.1111/j.1467-

8721.2008.00594.x.

[41] Palmer CA, Alfano CA. Sleep and emotion regulation: An organizing, integrative

review. Sleep Med Rev 2017;31:6–16. doi:10.1016/j.smrv.2015.12.006.

[42] Kahn M, Sheppes G, Sadeh A. Sleep and emotions: Bidirectional links and underlying

mechanisms. Int J Psychophysiol 2013;89:218–28.

doi:10.1016/j.ijpsycho.2013.05.010.

[43] Mulder R, Murray G, Rucklidge J. Common versus specific factors in psychotherapy:

RUNNING HEAD: EFFECT OF NON-PHARMACOLOGICAL SLEEP INTERVENTIONS ON DEPRESSION SYMPTOMS

27

opening the black box. The Lancet Psychiatry 2017;4:953–62. doi:10.1016/S2215-

0366(17)30100-1.

[44] Moher D, Liberati A, Tetzlaff J, Altman DG, Altman D, Antes G, et al. Preferred

reporting items for systematic reviews and meta-analyses: The PRISMA statement.

PLoS Med 2009;6:e1000097. doi:10.1371/journal.pmed.1000097.

[45] Higgins J, Green S. Cochrane handbook for systematic reviews of interventions.

Chichester: JohnWiley & Sons, Ltd; 2008.

[46] The Cochrane Collaboration. Review Manager (RevMan) 2014.

[47] Cohen J. Statistical Power Analysis for the Behavioral Sciences. New York:

Routledge; 1988.

[48] Ryan R. Heterogeneity and subgroup analyses in Cochrane Consumers and

Communication Review Group reviews: Planning the analysis at protocol stage 2016.

http://cccrg.cochrane.org.

[49] Field AP, Gillett R. How to do a meta-analysis. Br J Math Stat Psychol 2010;63:665–

94. doi:10.1348/000711010X502733.

[50] Cuijpers P, Straten A Van, Schaik A Van, Andersson G. Psychological treatment of

depression in primary care: a meta-analysis. Br J Gen Pract 2009:e51-60.

doi:10.3399/bjgp09X395139.

[51] Twomey C, Byrne M. Effectiveness of cognitive behavioural therapy for anxiety and

depression in primary care: a meta-analysis. Fam Pract 2017;32:3–15.

doi:10.1093/fampra/cmu060.

[52] Fiest KM, Walker JR, Bernstein CN, Graff LA, Zarychanski R, Abou-Setta AM, et al.

Systematic review and meta-analysis of interventions for depression and anxiety in

persons with multiple sclerosis. Mult Scler Relat Disord 2016;5:12–26.

doi:10.1016/j.msard.2015.10.004.

[53] van der Feltz-Cornelis CM, Nuyen J, Stoop C, Chan J, Jacobson AM, Katon W, et al.

Effect of interventions for major depressive disorder and significant depressive

symptoms in patients with diabetes mellitus: A systematic review and meta-analysis.

Gen Hosp Psychiatry 2010;32:380–95. doi:10.1016/j.genhosppsych.2010.03.011.

[54] Sheard T, Maguire P. The effect of psychological interventions on anxiety and

depression in cancer patients: Results of two meta-analyses. Br J Cancer

1999;80:1770–80. doi:10.1038/sj.bjc.6690596.

[55] Cuijpers P, Andersson G, Donker T, van Straten A. Psychological treatment of

depression: Results of a series of meta-analyses. Nord J Psychiatry 2011;65:354–64.

doi:10.3109/08039488.2011.596570.

[56] Belleville G, Cousineau H, Levrier K, St-Pierre-Delorme ME. Meta-analytic review of

the impact of cognitive-behavior therapy for insomnia on concomitant anxiety. Clin

Psychol Rev 2011;31:638–52. doi:10.1016/j.cpr.2011.02.004.

[57] *Taylor DJ, Pruiksma KE. Cognitive and behavioural therapy for insomnia (CBT-I) in

psychiatric populations: A systematic review. Int Rev Psychiatry 2014;26:205–13.

RUNNING HEAD: EFFECT OF NON-PHARMACOLOGICAL SLEEP INTERVENTIONS ON DEPRESSION SYMPTOMS

28

doi:10.3109/09540261.2014.902808.

[58] Weisz JR, Kuppens S, Ng MY, Eckshtain D, Ugueto AM, Vaughn-Coaxum R, et al.

What five decades of research tells us about the effects of youth psychological therapy:

A multilevel meta-analysis and implications for science and practice. Am Psychol

2017;72:79–117. doi:10.1037/a0040360.

[59] Weisz JR, McCarty CA, Valeri SM. Effects of psychotherapy for depression in

children and adolescents: A meta-analysis. Psychol Bull 2006;132:132–49.

doi:10.1037/0033-2909.132.1.132.

[60] Clement S, Schauman O, Graham T, Maggioni F, Evans-Lacko S, Bezborodovs N, et

al. What is the impact of mental health-related stigma on help-seeking? A systematic

review of quantitative and qualitative studies. Psychol Med 2015;45:11–27.

doi:10.1017/S0033291714000129.

[61] Blake M, Waloszek JM, Schwartz O, Raniti M, Simmons JG, Blake L, et al. The

SENSE Study : Post Intervention Effects of a Randomized Controlled Trial of a

Cognitive – Behavioral and Mindfulness-Based Group Sleep Improvement

Intervention Among At-Risk Adolescents. J Consult Clin Psychol 2016;84:1039–51.

[62] Casault L, Savard J, Ivers H, Savard MH. A randomized-controlled trial of an early

minimal cognitive-behavioural therapy for insomnia comorbid with cancer. Behav Res

Ther 2015;67:45–54. doi:10.1016/j.brat.2015.02.003.

[63] Chang YL, Chiou AF, Cheng SM, Lin KC. Tailored educational supportive care

programme on sleep quality and psychological distress in patients with heart failure: A

randomised controlled trial. Int J Nurs Stud 2016;61:219–29.

doi:10.1016/j.ijnurstu.2016.07.002.

[64] Christensen H, Batterham PJ, Gosling JA, Ritterband LM, Griffiths KM, Thorndike

FP, et al. Effectiveness of an online insomnia program (SHUTi) for prevention of

depressive episodes (the GoodNight Study): A randomised controlled trial. The Lancet

Psychiatry 2016;3:333–41. doi:10.1016/S2215-0366(15)00536-2.

[65] Currie SR, Wilson KG, Pontefract AJ, DeLaplante L. Cognitive-behavioural treatment

of insomnia secondary to chronic pain. Int J Nurs Stud 2000;68:407–16.

[66] Currie SR, Clark S, Hodgins DC, El-Guebaly N. Randomized controlled trial of brief

cognitive-behavioural interventions for insomnia in recovering alcoholics. Addiction

2004;99:1121–32. doi:10.1111/j.1360-0443.2004.00835.x.

[67] Dewald-Kaufmann JF, Oort FJ, Meijer AM. The effects of sleep extension and sleep

hygiene advice on sleep and depressive symptoms in adolescents: A randomized

controlled trial. J Child Psychol Psychiatry Allied Discip 2014;55:273–83.

doi:10.1111/jcpp.12157.

[68] Ebert DD, Thiart H, Laferton JAC, Berking M, Riper H, Cuijpers P, et al. Restoring

depleted resources: Efficacy and mechanisms of change of an internet-based unguided

recovery training for better sleep and psychological detachment from work. Heal

Psychol 2015;34:1240–51. doi:10.1037/hea0000277.

[69] Edinger JD, Wohlgemuth WK, Radtke RA, Marsh G, Quillian RE. Cognitive

RUNNING HEAD: EFFECT OF NON-PHARMACOLOGICAL SLEEP INTERVENTIONS ON DEPRESSION SYMPTOMS

29

Behavioral Therapy for Treatment of Chronic Insomnia: A Randomized Controlled

Trial. JAMA 2001;283:1856–64.

[70] Edinger JD, Wohlgemuth WK, Radtke RA, Coffman CJ, Carney CE. Dose-response

effects of cognitive-behavioral insomnia therapy: A randomized clinical trial. Sleep

2007;30:203–12. doi:10.1093/sleep/30.2.203.

[71] Freeman D, Sheaves B, Goodwin GM, Yu L, Nickless A, Harrison PJ, et al. The

effects of improving sleep on mental health (OASIS): a randomised controlled trial

with mediation analysis. The Lancet Psychiatry 2017;4:749–58. doi:10.1016/S2215-

0366(17)30328-0.

[72] Galovski TE, Blain LM, Elwood L, Gloth C, Fletcher TD, Harik JM. Augmenting

Cognitive Processing Therapy to Improve Sleep Impairment in PTSD: A Randomized

Controlled Trial. J Consult Cinical Psychol 2016;84:167–77.

doi:10.1037/ccp0000059.Augmenting.

[73] Gradisar M, Dohnt H, Gardner G, Paine S, Starkey K, Menne A, et al. A randomized

controlled trial of cognitive-behavior therapy plus bright light therapy for adolescent

delayed sleep phase disorder. Sleep 2011;34:1671–80.

doi:http://dx.doi.org/10.5665/sleep.1432.

[74] Ho FYY, Chung KF, Yeung WF, Ng THY, Cheng SKW. Weekly brief phone support

in self-help cognitive behavioral therapy for insomnia disorder: Relevance to

adherence and efficacy. Behav Res Ther 2014;63:147–56.

doi:10.1016/j.brat.2014.10.002.

[75] Horsch CH, Lancee J, Griffioen-Both F, Spruit S, Fitrianie S, Neerincx MA, et al.

Mobile Phone-Delivered Cognitive Behavioral Therapy for Insomnia: A Randomized

Waitlist Controlled Trial. J Med Internet Res 2017;19:e70.

[76] Hou Y, Hu P, Liang Y, Mo Z. Effects of Cognitive Behavioral Therapy on Insomnia of

Maintenance Hemodialysis Patients. Cell Biochem Biophys 2014;69:531–7.

doi:10.1007/s12013-014-9828-4.

[77] Irwin MR, Olmstead R, Carrillo C, Sadeghi N, Nicassio P, Ganz PA, et al. Tai Chi

Chih Compared With Cognitive Behavioral Therapy for the Treatment of Insomnia in

Survivors of Breast Cancer : A Randomized , Partially Blinded , Noninferiority Trial. J

Clin Oncol 2017;35:2656–65.

[78] Jungquist CR, Brien CO, Matteson-rusby S, Smith MT, Pigeon WR, Xia Y, et al. The

Efficacy of Cognitive Behavioral Therapy for Insomnia in Patients with Chronic Pain.

Sleep Med 2010;11:302–9. doi:10.1016/j.sleep.2009.05.018.The.

[79] Kapella MC, Herdegen JJ, Perlis ML, Shaver JL, Larson JL, Law JA, et al. Cognitive

behavioral therapy for insomnia comorbid with COPD is feasible with preliminary

evidence of positive sleep and fatigue effects 2011;6:625–35.

doi:10.2147/COPD.S24858.

[80] Lancee J, van den Bout J, van Straten A, Spoormaker VI. Internet-delivered or mailed

self-help treatment for insomnia? A randomized waiting-list controlled trial. Behav

Res Ther 2012;50:22–9. doi:10.1016/j.brat.2011.09.012.

RUNNING HEAD: EFFECT OF NON-PHARMACOLOGICAL SLEEP INTERVENTIONS ON DEPRESSION SYMPTOMS

30

[81] Lancee J, Eisma MC, van Straten A, Kamphuis JH. Sleep-Related Safety Behaviors

and Dysfunctional Beliefs Mediate the Efficacy of Online CBT for Insomnia: A

Randomized Controlled Trial. Cogn Behav Ther 2015;44:406–22.

doi:10.1080/16506073.2015.1026386.

[82] Lancee J, van Straten A, Morina N, Kaldo V, Kamphuis JH. Guided Online or Face-to-

Face Cognitive Behavioral Treatment for Insomnia: A Randomized Wait-List

Controlled Trial. Sleep 2016;39:183–91. doi:10.5665/sleep.5344.

[83] Lancee J, Yasiney SL, Brendel RS, Boffo M, Patrick J, Clarke F, et al. Attentional bias

modification training for insomnia : A double-blind placebo controlled randomized

trial 2017.

[84] Lichstein KL, Wilson NM, Johnson CT. Psychological treatment of secondary

insomnia. Psychol Aging 2000;15:232–40. doi:10.1037//0882-7974.I5.2.232.

[85] Margolies SO, Rybarczyk B, Vrana SR, Leszczyszyn DJ, Lynch J. Efficacy of a

cognitive-behavioral treatment for insomnia and nightmares in afghanistan and iraq

veterans with PTSD. J Clin Psychol 2013;69:1026–42. doi:10.1002/jclp.21970.

[86] McCurry SM, Logsdon RG, Vitiello M V, Teri L. Successful behavioral treatment for

reported sleep problems in elderly caregivers of dementia patients: A controlled study.

Journals Gerontol – Ser B Psychol Sci Soc Sci 1998;53:122–9.

[87] McCurry SM, LaFazia DM, Pike KC, Logsdon RG, Teri L. Development and

evaluation of a sleep education program for older adults with dementia living in adult

family homes. Am J Geriatr Psychiatry 2012;20:494–504.

[88] Mimeault V, Morin CM. Self-help Treatment for Insomnia: Bibliotherapy With and

Without Professional Guidance. J Consult Clin Psychol 1999;67:511–9.

[89] Morin C, Beaulieu-Bonneau S, LeBlanc M, Savard J. Self-help treatment for insomnia:

a randomized controlled trial. Sleep 2005;28:1319–27.

[90] Moseley L, Gradisar M. Evaluation of a school-based intervention for adolescent sleep

problems. Sleep 2009;32:334–341 8p.

[91] Nguyen S, Mckay A, Wong D, Rajaratnam SM, Spitz G, Williams G, et al. Cognitive

Behavior Therapy to Treat Sleep Disturbance and Fatigue After Traumatic Brain

Injury : A Pilot Randomized Controlled Trial. Arch Phys Med Rehabil 2017;98:1508–

1517.e2. doi:10.1016/j.apmr.2017.02.031.

[92] Pigeon WR, Moynihan J, Matteson-Rusby S, Jungquist CR, Xia Y, Tu X, et al.

Comparative effectiveness of CBT interventions for co-morbid chronic pain &

insomnia: A pilot study. Behav Res Ther 2012;50:685–9.

doi:10.1016/j.brat.2012.07.005.

[93] Riedel, Brant W, Lichstein KL, Peterson BA, Epperson MT, Means MK, Aguillard

RN. A Comparison of the Efficacy of Stimulus Control for Medicated and

Nonmedicated Insomniacs. Behav Modif 1998;22:3–28.

[94] Rios Romenets S, Creti L, Fichten C, Bailes S, Libman E, Pelletier A, et al. Doxepin

and cognitive behavioural therapy for insomnia in patients with Parkinson’s disease –

A randomized study. Park Relat Disord 2013;19:670–5.

RUNNING HEAD: EFFECT OF NON-PHARMACOLOGICAL SLEEP INTERVENTIONS ON DEPRESSION SYMPTOMS

31

doi:10.1016/j.parkreldis.2013.03.003.

[95] Ritterband LM, Bailey ET, Thorndike, Frances P. Lord HR, Farrell‐Carnahan, Leah
Baum LD. Initial evaluation of an Internet intervention to improve the sleep of cancer

survivors with insomnia. Psychooncology 2012;21:695–705.

[96] Savard J, Simard S, Ivers H, Morin CM. Randomized study on the efficacy of

cognitive-behavioral therapy for insomnia secondary to breast cancer, part I: Sleep and

psychological effects. J Clin Oncol 2005;23:6083–96. doi:10.1200/JCO.2005.09.548.

[97] Savard J, Ivers H, Savard M-H, Morin CM. Is a Video-Based Cognitive Behavioral

Therapy for Insomnia as Efficacious as a Professionally Administered Treatment in

Breast Cancer? Results of a Randomized Controlled Trial. Sleep 2014;37:1305–14.

doi:10.5665/sleep.3918.

[98] Stremler R, Hodnett E, Kenton L, Lee K, Weiss S, Weston J, et al. Effect of

behavioural-educational intervention on sleep for primiparous women and their infants

in early postpartum: Multisite randomised controlled trial. BMJ 2013;346:1–14.

doi:10.1136/bmj.f1164.

[99] Suzuki E, Tsuchiya M, Hirokawa K, Taniguchi T, Mitsuhashi T, Kawakami N.

Evaluation of an Internet-Based Self-Help Program for Better Quality of Sleep among

Japanese Workers: A Randomized Controlled Trial. J Occup Health 2008;50:387–99.

[100] Swift N, Stewart R, Andiappan M, Smith A, Espie CA, Brown JSL. The effectiveness

of community day-long CBT-I workshops for participants with insomnia symptoms: A

randomised controlled trial. J Sleep Res 2012;21:270–80. doi:10.1111/j.1365-

2869.2011.00940.x.

[101] Talbot LS, Maguen S, Metzler TJ, Schmitz M, McCaslin SE, Richards A, et al.

Cognitive Behavioral Therapy for Insomnia in Posttraumatic Stress Disorder: A

Randomized Controlled Trial. Sleep 2014;37:327–41. doi:10.5665/sleep.3408.

[102] Tang NKY, Goodchild CE, Salkovskis PM. Hybrid cognitive-behaviour therapy for

individuals with insomnia and chronic pain: A pilot randomised controlled trial. Behav

Res Ther 2012;50:814–21. doi:10.1016/j.brat.2012.08.006.

[103] Taylor DJ, Zimmerman MR, Gardner CE, Williams JM, Grieser EA, Tatum JI, et al. A

pilot randomized controlled trial of the effects of cognitive-behavioral therapy for

insomnia on sleep and daytime functioning in college students. Behav Ther

2014;45:376–89. doi:http://dx.doi.org/10.1016/j.beth.2013.12.010.

[104] Thorndike FP, Ritterband LM, Gonder-Frederick LA, Lord HR, Ingersoll KS, Morin

CM. A Randomized Controlled Trial of an Internet Intervention for Adults with

Insomnia: Effects on Comorbid Psychological and Fatigue Symptoms. J Clin Psychol

2013;69:1078–93. doi:10.1002/jclp.22032.A.

[105] Ulmer CS, Edinger JD, Calhoun PS. A multi-component cognitive-behavioral

intervention for sleep disturbance in Veterans with PTSD: A pilot study. J Clin Sleep

Med 2011;7:57–68.

[106] van Straten A, Cuijpers P, Smit F, Spermon M, Verbeek I. Self-help treatment for

insomnia through television and book: A randomized trial. Patient Educ Couns

RUNNING HEAD: EFFECT OF NON-PHARMACOLOGICAL SLEEP INTERVENTIONS ON DEPRESSION SYMPTOMS

32

2009;74:29–34. doi:10.1016/j.pec.2008.07.050.

[107] Van Straten A, Emmelkamp J, De Wit J, Lancee J, Andersson G, Van Someren EJW,

et al. Guided Internet-delivered cognitive behavioural treatment for insomnia: A

randomized trial. Psychol Med 2014;44:1521–32. doi:10.1017/S0033291713002249.

[108] Wagley JN, Rybarczyk B, Nay WT, Danish S, Lund HG. Effectiveness of abbreviated

CBT for insomnia in psychiatric outpatients: Sleep and depression outcomes. J Clin

Psychol 2013;69:1043–55. doi:10.1002/jclp.21927.

[109] Watanabe N, Furukawa TA, Shimodera S, Morokuma O, Katsuki F, Fujita H, et al.

Brief Behavioral Therapy for Refactory Insomnia in Residual Depression: An

Assessor-Blind Randomized Controlled Trial. J Clin Psychiatry 2011;72:1651–8.

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Tables

Table 1. Characteristics of studies included in the meta-analysis

Study County Participants Intervention Depression

measure
Sleep
measure

Blake et al. 2016 [61] Australia Adolescents (aged 12–17) with

high anxiety and sleep difficulties

CBT/mindfulness-based

group sleep intervention

CESD PSQI

Casault et al. 2015 [62] Canada Adults diagnosed with cancer

with comorbid insomnia

Self-help CBT-I with

telephone support

HADS ISI

Chang et al. 2016 [63] Taiwan Adults with heart failure Educational supportive care

programme

HADS PSQI

Christensen et al. 2016 [64] Australia Adult internet users

with insomnia

and subclinical depression

Online insomnia self-help

programme

PHQ-9 ISI

Currie et al. 2000 [65] Canada Adults with insomnia secondary

to chronic pain

Group CBT-I

BDI PSQI

Currie et al. 2004 [66] Canada Adult recovering alcoholics with

insomnia

Brief CBT-based insomnia

programme

BDI PSQI

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Dewald-Kaufmann et al.

2014 [67]

Netherlands Adolescents (aged 12-19) with

chronic sleep reduction

Gradual sleep extension and

sleep hygiene advice

CDI CSRQ

Ebert et al. 2015 [68] Germany Adult teachers with sleeping

problems

Online CBT-I based recovery

training programme

CESD PSQI

Edinger et al. 2001 [69] USA Adults with chronic primary

sleep-

maintenance insomnia

Individual CBT-I BDI ISQ

Edinger et al. 2007 [70] USA Adults with primary sleep-

maintenance insomnia
Individual CBT-I BDI ISQ

Freeman et al. 2017 [71] UK Adult university students with

insomnia

Online CBT-I delivered via a

media-rich web application

PHQ-9 ISI

Galovski et al. 2016 [72] USA Adult female interpersonal assault

survivors with sleep impairment

Sleep-directed hypnosis BDI-II PSQI

Gradisar et al. 2011 [73] Australia Adolescents (aged 11-18)

diagnosed with delayed sleep

phase disorder

Individual CBT plus morning

bright light

MFQ None

Ho et al. 2014 [74] China Adult internet users with insomnia Online self-help CBT-I with HADS PSQI

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telephone support

Horsch et al. 2017 [75] Netherlands Adult with insomnia and an

Android mobile phone

CBT-I delivered via an

automated mobile phone app

CESD PSQI

Hou et al. 2014 [76] China Adults with end stage renal

disease and comorbid insomnia

Individual CBT-I SCL-90 PSQI

Irwin et al. 2017 [77] USA Adult survivors of breast cancer

with insomnia

Group CBT-I IDS-C PSQI

Jungquist et al. 2010 [78] UK Adults with insomnia comorbid

with chronic pain

Individual CBT-I

BDI ISI

Kapella et al. 2011 [79] USA Adults with insomnia and chronic

obstructive pulmonary disease

Individual CBT-I POMS-D PSQI

Lancee et al. 2012 [80] Netherlands Adult internet users with insomnia Online self-help CBT-I

CESD SLEEP-50

Lancee et al. 2015 [81] Netherlands Adult internet users with insomnia Online self-help CBT-I

CESD ISI

Lancee et al. 2016 [82] Netherlands Adult internet users with insomnia Online guided CBT-I CESD ISI

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Lancee et al. 2017 [83] Netherlands Adult internet users with insomnia

Attentional bias modification

training

CESD ISI

Lichstein et al. 2000 [84] USA Older adults (aged 58+) with

insomnia secondary to illness

Sleep hygiene, stimulus control

and relaxation

GDS None

Margolies et al. 2013 [85] USA Adult veterans with PTSD and

sleep disturbance

CBT-I combined with imagery

rehearsal therapy

PHQ-9 PSQI

McCurry et al. 1998 [86] USA Older adult (aged 50+) dementia

caregivers with sleep problems

Group educational and

behavioural intervention

CESD PSQI

McCurry et al. 2012 [87] USA Older adults with dementia

resident in small care homes

Sleep education for care-staff CSDD None

Mimeault & Morin 1999

[88]

Canada Adults with primary insomnia Self-help CBT-I with

telephone support
BDI PSQI

Morin et al. 2005 [89] Canada Adults with insomnia symptoms

Self-help CBT-I BDI-II PSQI

Moseley et al. 2009 [90] Australia Adolescent high school students CBT-I-based classroom sleep DASS-21 None

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(aged 15/16) education programme

Nguyen et al. 2017 [91] Australia Adults with

traumatic brain injury

and sleep/fatigue complaints

Individual CBT-I adapted for

traumatic brain injury
HADS PSQI

Pigeon et al. 2012 [92] USA Adults with co-occurring chronic

pain and chronic insomnia

CBT for insomnia and pain CESD ISI

Riedel et al. 1998 [93] USA Adults with insomnia

Individual stimulus control

sessions

BDI None

Rios Romenets et al. 2013

[94]

Canada Adults with Parkinson’s disease

and insomnia

Sleep hygiene training, CBT-I

and bright light therapy

BDI ISI

Ritterband et al. 2012 [95] USA Adult internet users in remission

from cancer with secondary

insomnia

Online CBT-I HADS ISI

Savard et al. 2005 [96] Canada Adult women with insomnia

secondary to breast cancer

Group CBT-I HADS ISI

Savard et al. 2014 [97] Canada Adult women with breast cancer

and insomnia symptoms who

Individual CBT-I HADS ISI

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received radiation therapy

Stremler et al. 2013 [98] Canada Adult women who had recently

given birth for the first time

Sleep education and advice EPDS GSDS

Suzuki et al. 2008 [99] Japan Adult workers with a desire to

improve their sleep quality

Online CBT-based self-help

programme

K6 PSQI

Swift et al. 2012 [100] UK Adults who responded to a flyer

advertising sleep workshops

One-day CBT-I workshop BDI ISI

Talbot et al. 2014 [101] USA Adults with PTSD and insomnia

Individual CBT-I BDI ISI

Tang et al. 2012 [102] UK Adults with chronic pain and

insomnia

Individual hybrid CBT for

insomnia and chronic pain

HADS ISI

Taylor et al. 2014 [103] USA Adult college students with

insomnia

Individual CBT-I QIDS PSQI

Thorndike et al. 2013 [104] USA Adult internet users with insomnia

Online self-help CBT-I BDI-II ISI

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Ulmer et al. 2011 [105] USA Adult veterans meeting criteria for

PTSD and insomnia

Sleep intervention for PTSD

(CBT and imagery rehearsal

therapy)

PHQ-2 PSQI

van Straten et al. 2009

[106]

Netherlands Adults with insomnia symptoms Self-help CBT-I delivered via a

book and television

CESD SEF

van Straten et al. 2014

[107]

Netherlands Adults with insomnia Online CBT-I with support of

online coach

CESD PSQI

Wagley et al. 2013 [108] USA Adult psychiatric outpatients with

low sleep quality and depression

symptoms

Two session individual CBT-I PHQ-9 PSQI

Watanabe et al. 2011 [109] Japan Adult psychiatric outpatients with

depression and insomnia

Individual CBT-I HDRS PSQI

Abbreviations. BDI = Beck depression inventory; CBT-I = cognitive behavioural therapy for insomnia; CDI = children’s depression inventory;

CESD = centre for epidemiological studies depression scale; CSDD = Cornell Scale for Depression in Dementia; CSRQ = chronic sleep

reduction questionnaire; DASS = depression anxiety stress scale; GDS = geriatric depression scale; GSDS = general sleep disturbance scale;

HADS = hospital anxiety and depression scale (depression subscale); HDRS = Hamilton depression rating scale; ISI = insomnia severity index;

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K6 = Kessler psychological distress scale; MFQ = mood and feeling questionnaire; PHQ = patient health questionnaire; POMS-D = profile of

mood states depression subscale; PSQI = Pittsburgh sleep quality inventory; SCI = sleep condition indicator; SCL-90 = symptom checklist

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Figure Legends

Figure 1. Flow diagram of study selection process

Figure 2. Risk of bias graph

Figure 3. Forrest plot for meta-analysis of the effect of non-pharmacological sleep

interventions on depression symptoms.