Cited by 652Sleep and related disordersDigital Mental Health InterventionsCOVID-19 and Mental Health

The DOI matches its Crossref record; 38 of the 38 references it cites were found in a registry or an index; 2 of the 34 sources its claims cite were checked for support.

The effects of improving sleep on mental health (OASIS): a randomised controlled trial with mediation analysis

Open access

Abstract

BACKGROUND: Sleep difficulties might be a contributory causal factor in the occurrence of mental health problems. If this is true, improving sleep should benefit psychological health. We aimed to determine whether treating insomnia leads to a reduction in paranoia and hallucinations. METHODS: We did this single-blind, randomised controlled trial (OASIS) at 26 UK universities. University students with insomnia were randomly assigned (1:1) with simple randomisation to receive digital cognitive behavioural therapy (CBT) for insomnia or usual care, and the research team were masked to the treatment. Online assessments took place at weeks 0, 3, 10 (end of therapy), and 22. The primary outcome measures were for insomnia, paranoia, and hallucinatory experiences. We did intention-to-treat analyses. The trial is registered with the ISRCTN registry, number ISRCTN61272251. FINDINGS: Between March 5, 2015, and Feb 17, 2016, we randomly assigned 3755 participants to receive digital CBT for insomnia (n=1891) or usual practice (n=1864). Compared with usual practice, the sleep intervention at 10 weeks reduced insomnia (adjusted difference 4·78, 95% CI 4·29 to 5·26, Cohen's d=1·11; p<0·0001), paranoia (-2·22, -2·98 to -1·45, Cohen's d=0·19; p<0·0001), and hallucinations (-1·58, -1·98 to -1·18, Cohen's d=0·24; p<0·0001). Insomnia was a mediator of change in paranoia and hallucinations. No adverse events were reported. INTERPRETATION: To our knowledge, this is the largest randomised controlled trial of a psychological intervention for a mental health problem. It provides strong evidence that insomnia is a causal factor in the occurrence of psychotic experiences and other mental health problems. Whether the results generalise beyond a student population requires testing. The treatment of disrupted sleep might require a higher priority in mental health provision. FUNDING: Wellcome Trust.

Overview

AI snapshot

Written from the paper’s full text.

TL;DR

In the OASIS trial, digital CBT for insomnia in university students reduced insomnia and produced small sustained reductions in paranoia and hallucinations compared with usual practice. Mediation analyses suggested that improvements in insomnia accounted for a substantial portion of the reductions in psychotic experiences.

Key findings

  • Among 3755 randomised participants (digital CBT n=1891; usual practice n=1864), at 10 weeks the intervention reduced insomnia (adjusted difference 4·78, 95% CI 4·29–5·26, Cohen’s d=1·11), paranoia (−2·22, −2·98 to −1·45, d=0·19), and hallucinations (−1·58, −1·98 to −1·18, d=0·24); all p<0·0001.
  • Insomnia mediated change in psychotic experiences: week 3 insomnia explained 29·5% of the paranoia effect and 20·7% of the hallucination effect at week 10; week 10 insomnia explained 57·8% and 38·6%, respectively. Reverse-direction mediation was much smaller (paranoia 3·8%; hallucinations 3·4%).
  • Secondary outcomes improved for depression, anxiety, prodromal symptoms, nightmares, psychological wellbeing, and functioning, and participants were less likely to meet criteria for depressive episode, anxiety disorder, or ultra-high risk of psychosis. However, mania symptoms increased and risk of meeting criteria for a manic episode was greater; no adverse events were reported.

Methods

  • Single-blind, randomised controlled trial at 26 UK universities. Participants were university students aged 18 or older with a positive insomnia screen (SCI score ≤16) and no exclusion criteria; recruitment ran March 5, 2015, to Feb 17, 2016.
  • Participants were randomly assigned 1:1 via simple randomisation to digital CBT for insomnia (Sleepio) or usual practice, with online assessments at weeks 0, 3, 10, and 22. Primary outcomes were insomnia (SCI-8), paranoia (GPTS part B), and hallucinations (SPEQ hallucinations subscale).
  • Intention-to-treat analyses used linear mixed effects models with time, randomised group, baseline score, sex, and course level as fixed effects and random effects for students nested within universities. Mediation used a Baron-and-Kenny-like approach with linear mixed effects models.

Limitations

  • The paper states: reliance on self-report questionnaires; samples were predominantly in the non-clinical range of psychotic experiences; participants were self-selecting; generalisability beyond students is unknown; high dropout, especially in the treatment group, may bias results; and mediation cannot fully capture temporal order or rule out reverse causation.
  • The text also makes evident that treatment uptake was low: 69% logged on for at least one session and 18% accessed all six sessions, with treatment effects greater among completers.
  • The paper reports no adverse events, but also reports increased mania symptoms and greater risk of meeting manic episode criteria with the sleep treatment, which it discusses as possibly reflecting increased wellbeing or problematic manic symptoms.

Model-written summary. Check it against the paper before relying on it.

Integrity signals

Registry

Crossref · 10.1016/s2215-0366(17)30328-0

Cites

38 of 38 references verified0 citation errors · 0 not checkable

Statistics

Nothing to recompute.

Figures

Figure Trial profile SCI=Sleep Condition Indicator. *Some participants excluded for two or more reasons. †Not all participants accessed all treatment sessions. ‡Had at least one measurement at week 3, 10, or 22.
Figure Trial profile SCI=Sleep Condition Indicator. *Some participants excluded for two or more reasons. †Not all participants accessed all treatment sessions. ‡Had at least one measurement at week 3, 10, or 22.CC BY · PubMed Central

Verification

Claims the paper makes

39 Own result · 28 Own method · 22 Not checked yet · 21 Own interpretation · 2 No basis given · 1 Supported · 1 Supported so far

Verify all 32 references — free account

Show all 68 claims

  • It may state two separate claims as one. 16
  • Probably not a substantial claim. 36
46 of 46
  • The paper relies on this without support.

    Usual practice is likely to mean receiving little or no treatment.

    “usual care, which is likely to mean receiving little or no treatment”
    “The amount of treatment input was likely to be minimal, with prescription of medication for a small proportion.”
  • The authors state this as an assumption.

    The data are missing at random.

    “The method has the advantage of implicitly accounting for data missing at random.”
  • The paper relies on this without support.

    There are multiple, independent psychotic experiences.

    “There are multiple, independent, psychotic experiences.”
  • The authors state this as an assumption.

    The sleep treatment first changes the occurrence of insomnia.

    “the causal argument rests on the plausible assumption that the sleep treatment first changes the occurrence of insomnia, since that was the topic of the intervention”
  • The paper relies on this without support.

    A gap exists in mental health services regarding intervention for early, relatively non-specific presentations.

    “a gap exists in mental health services regarding intervention for early, relatively non-specific presentations”
  • The paper relies on this without support.

    Young people with incipient disorders might be very reluctant to seek help for psychiatric problems.

    “Young people with incipient disorders might be very reluctant to seek help for psychiatric problems.”
  • The paper relies on this without support.

    Trouble sleeping is a common complaint with little stigma.

    “Trouble sleeping is a common complaint with little stigma.”
7 of 7

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Metadata

Authors
Freeman, D., Sheaves, B., Goodwin, G. M., Yu, L.-M., Nickless, A., Harrison, P. J., Emsley, R., Luik, A. I., Foster, R. G., Wadekar, V., Hinds, C., Gumley, A., Jones, R., Lightman, S., Jones, S., Bentall, R., Kinderman, P., Rowse, G., Brugha, T., Blagrove, M., Gregory, A. M., Fleming, L., Walklet, E., Glazebrook, C., Davies, E. B., Hollis, C., Haddock, G., John, B., Coulson, M., Fowler, D., Pugh, K., Cape, J., Moseley, P., Brown, G., Hughes, C., Obonsawin, M., Coker, S., Watkins, E., Schwannauer, M., MacMahon, K., Siriwardena, A. N., & Espie, C. A.
Affiliations
  • National Health Service (GB)
  • University of Oxford (GB)
  • Manchester Academic Health Science Centre (GB)
  • Warneford Hospital (GB)
  • Gartnavel General Hospital (GB)
  • University of Plymouth (GB)
  • University of Bristol (GB)
  • University of Sheffield (GB)
  • University of Liverpool (GB)
  • University of Leicester (GB)
  • Swansea University (GB)
  • Goldsmiths University of London (GB)
  • University of Strathclyde (GB)
  • University of Worcester (GB)
  • University of Nottingham (GB)
  • University of Manchester (GB)
  • University of South Wales (GB)
  • Middlesex University London (GB)
  • University of Sussex (GB)
  • Sussex Partnership NHS Foundation Trust (GB)
  • University College London (GB)
  • University of Lancashire (GB)
  • Royal Holloway University of London (GB)
  • University of Cambridge (GB)
  • University of Exeter (GB)
  • University of Edinburgh (GB)
  • University of Lincoln (GB)
Corresponding author
Freeman, Daniel
Venue
The Lancet Psychiatry
Publisher
Elsevier BV
Published
2017-10
Volume
4
Issue
10
Pages
749-758
ISSN
2215-0366 (ISSN-L)
OpenAlex
W2753665614
Cited by
652
References
38
Citations by year
2026: 53 · 2025: 68 · 2024: 73 · 2023: 80 · 2022: 83 · 2021: 98 · 2020: 83 · 2019: 55 · 2018: 46 · 2017: 11
FWCI
69.44
Type
journal article
Language
en
Open access
Locations
  • The Lancet Psychiatry (publishedVersion, cc-by)
  • Europe PMC (PubMed Central) (publishedVersion, cc-by)
  • PubMed Central (publishedVersion, cc-by)
  • PubMed (publishedVersion)
  • Open Research Exeter (University of Exeter) (publishedVersion, cc-by)
  • CLOK (University of Central Lancashire) (acceptedVersion)
  • ENLIGHTEN (Jurnal Bimbingan dan Konseling Islam) (acceptedVersion)
  • Research Repository (University of Gloucestershire) (acceptedVersion)
  • Goldsmiths (University of London) (acceptedVersion)
  • Lincoln Repository (University of Lincoln) (acceptedVersion)
  • White Rose Research Online (University of Leeds, The University of Sheffield, University of York) (acceptedVersion)
  • Northumbria Research Link (Northumbria University) (acceptedVersion)
  • Strathprints: The University of Strathclyde institutional repository (University of Strathclyde) (acceptedVersion)
  • UEA Digital Repository (University of East Anglia) (acceptedVersion)
  • Leicester Research Archive (University of Leicester) (acceptedVersion, other-oa)
  • Research Repository (University of Gloucestershire) (submittedVersion, other-oa)
  • Explore Bristol Research (submittedVersion, cc-by)
  • Sussex Research Online (University of Sussex) (submittedVersion, cc-by)
  • Worcester Research and Publications (University of Worcester) (submittedVersion)
  • Lancaster EPrints (Lancaster University) (submittedVersion)
  • Figshare (submittedVersion, cc-by)
  • Figshare (submittedVersion)
  • Research Portal (King's College London) (submittedVersion, cc-by)
  • PEARL (University of Plymouth) (submittedVersion)
  • Research Explorer (The University of Manchester) (submittedVersion, cc-by)
  • Edinburgh Research Explorer (University of Edinburgh) (submittedVersion, cc-by)
  • Bristol Research (University of Bristol) (submittedVersion, cc-by)
Funders
  • Wellcome Trust (098461/Z/12/Z)
  • National Institute for Health and Care Research (RP-2014-05-003, NF-SI-0514-10119)
  • University of Oxford
Topics
  • Social Sciences › Psychology › Experimental and Cognitive Psychology › Sleep and related disorders
  • Social Sciences › Psychology › Applied Psychology › Digital Mental Health Interventions
  • Social Sciences › Psychology › Clinical Psychology › COVID-19 and Mental Health
Keywords
insomnia, cognitive behavioral therapy for insomnia, paranoia, hallucinations, psychotic experiences, sleep disruption, university students, mental health, mediation analysis, digital psychological interventions
MeSH terms
Adolescent, Adult, Female, United Kingdom, Hallucinations, Humans, Sleep Initiation and Maintenance Disorders, Male, Mental Health, Paranoid Disorders, Sleep, Students, Cognitive Behavioral Therapy, Treatment Outcome, Young Adult

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