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Cited by 39Schizophrenia research and treatmentSleep and related disordersSleep and Wakefulness Research

Sleep duration and psychotic experiences in patients at risk of psychosis: a secondary analysis of the EDIE-2 trial

Open access
Reeve, S., Nickless, A., Sheaves, B., Hodgekins, J., Stewart, S.L.K., Gumley, A., Fowler, D., Morrison, A. +1 more·2019·Schizophrenia Research
DOI 10.1016/j.schres.2018.08.006PMC PMC6406020
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Abstract

Sleep disturbance is common among individuals at risk of psychosis, yet few studies have investigated the relationship between sleep disturbance and clinical trajectory. The Early Detection and Intervention Evaluation (EDIE-2) trial provides longitudinal data on sleep duration and individual psychotic experiences from a cohort of individuals at risk of psychosis, which this study utilises in an opportunistic secondary analysis. Shorter and more variable sleep was hypothesised to be associated with more severe psychotic experiences and lower psychological wellbeing. Mixed effect models were used to test sleep duration and range as predictors of individual psychotic experiences and psychological wellbeing over the 12-24 months (with assessments every 3 months) in 160 participants. Shorter sleep duration was associated with more severe delusional ideas and hallucinations cross-sectionally and longitudinally. The longitudinal relationships did not remain significant after conservative controls were added for the previous severity of psychotic experiences. No significant relationships were found between the sleep variables and other psychotic experiences (e.g. cognitive disorganisation), or psychological wellbeing. The results support a relationship between shorter sleep duration and delusional ideas and hallucinations. Future studies should focus on improving sleep disturbance measurement, and test whether treating sleep improves clinical trajectory in the at-risk group.

AI snapshot

Written from the paper’s full text.

TL;DR

In a secondary analysis of the EDIE-2 trial (n=160 individuals at risk of psychosis), shorter bad-night sleep duration was cross-sectionally and longitudinally associated with more severe delusional ideas and hallucinations. However, longitudinal relationships did not remain significant after conservative control for previous psychotic experience severity, and no relationships were found with other psychotic experiences or psychological wellbeing.

Key findings

  • Cross-sectionally, shorter bad-night sleep duration was associated with more severe non-bizarre ideas (estimate −0.402, p=0.004), perceptual abnormalities (−0.327, p=0.010), and psychotic experience distress (−1.170, p=0.005); narrower sleep duration range was associated with more severe non-bizarre ideas (−0.331, p=0.012), contrary to the hypothesis.
  • In longitudinal step 1, previous shorter bad-night sleep duration predicted later non-bizarre ideas (−0.432, p=0.003) and perceptual abnormalities (−0.324, p=0.017); previous narrower range predicted later non-bizarre ideas (−0.281, p=0.039); distress did not reach significance (p=0.078).
  • After controlling for later sleep (step 2), previous bad-night sleep duration remained significant for later non-bizarre ideas (−0.383, p=0.030); after adding previous psychotic experience severity (step 3), only the cross-sectional relationship between shorter bad-night sleep and more severe non-bizarre ideas remained significant (−0.365, p=0.023), and no previous sleep variables remained significant predictors.
  • No significant relationships were found between sleep variables and unusual thought content, disorganised speech, depression (BDI-PC), or quality of life (MANSA); e.g., depression with bad-night sleep duration p=0.226, quality of life with bad-night sleep duration p=0.330.

Methods

  • Secondary analysis of the EDIE-2 trial; final sample of 160 participants aged 14–35 at risk of psychosis (mean age 20.9 years, SD 4.2; 61.1% male; 91.8% white; 50% monitoring plus cognitive therapy, 50% monitoring only), after excluding Birmingham and Cambridge sites and participants without both good- and bad-night sleep duration data.
  • Sleep was self-reported average duration on “good” and “bad” nights over the past three months from the Economic Patient Questionnaire; the study used bad-night sleep duration and sleep duration range (good minus bad). Psychotic experiences were measured with CAARMS positive-dimension subscales (Unusual Thought Content, Non-Bizarre Ideas, Perceptual Abnormalities, Disorganised Speech) plus distress; depression with BDI-PC; quality of life with MANSA. Assessments occurred at baseline and every 3 months up to 24 months.
  • Analysis used SPSS v23 with pre-specified stepped linear mixed effects models, including site and treatment allocation as factors; cross-sectional models tested hypotheses 1 and 3, and longitudinal models tested hypothesis 2 in three steps adding later sleep and previous psychotic experience severity. Significance was set at p≤0.05.

Limitations

  • Stated: EDIE-2 did not focus on sleep; sleep duration estimates lacked frequency of good versus bad nights, average sleep time/variability, and sleep timing/circadian context; sleep predictors were collinear (bad-night duration and range correlated r=−0.756, p<0.001) and highly correlated over time; controlling for site and treatment reduced power; age, occupational status, and substance abuse could not be controlled.
  • Stated: the low transition rate to psychosis (9.4%) prevented testing transition as an outcome; BDI-PC used dimensionally may have lacked sensitivity, and lower completion of depression/quality-of-life measures may have reduced power.
  • Evident from the text: many reported associations would not survive conservative multiple-testing correction (authors argue planned comparisons make correction inappropriate); the sample was predominantly male, white, and recruited from UK sites, limiting generalisability; sleep was self-reported and indirect rather than objectively measured.

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

Integrity signals

Registry

Crossref · 10.1016/j.schres.2018.08.006

Cites

39 of 39 references verified0 citation errors · 0 not checkable

Statistics

Nothing to recompute.

Claims the paper makes

0 of 47 cited sources checked · 0 supported · 0 flagged

  • Findingown data

    Narrower sleep range is associated with increased severity of later delusional ideas, contrary to hypothesis.

    “Narrower sleep range was associated with increased severity of later delusional ideas, again contrary to hypothesis.”
    Quote in the paperSubstantial claim
  • Findingown data

    Previous shorter bad night sleep duration was significantly associated with increased severity of later perceptual abnormalities longitudinally.

    “there were significant relationships between previous shorter bad night sleep duration and increased severity of later NBI and PA”
    Quote in the paperSubstantial claim
  • Findingown data

    The cognitive therapy group had lower severity in the Unusual Thought Content dimension of the CAARMS than those who received monitoring alone.

    “The cognitive therapy group had lower severity in the Unusual Thought Content and Perceptual Abnormality dimensions of the CAARMS than those who received monitoring alone.”
    Quote in the paperNot a substantial claim
  • Findingown data

    Shorter bad night sleep duration is a significant predictor of later delusional ideas and hallucinations.

    “These results suggest that shorter bad night sleep duration is a significant predictor of later delusional ideas and hallucinations.”
    Quote in the paperSubstantial claim
  • Findingown data

    In the cross-sectional model, no significant relationship was found between the sleep variables and disorganised speech.

    “No significant relationships between bad night sleep duration or sleep duration range were found for either unusual thought content (UTC) or disorganised speech (DS) in this cross-sectional model.”
    Quote in the paperNot a substantial claim
  • May combine two claims. 20
  • Classified as probably not a substantial claim. 34
  • The quote only partly states this claim. 1

  • May combine two claims.

    Findingown data

    Neither bad sleep duration nor sleep duration range at either the previous or later time point had a significant predictive effect on other psychotic experience severities.

    “However, neither bad sleep duration nor sleep duration range (at either the previous or later time point) had a significant predictive effect on other psychotic experience severities.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    Neither bad night sleep duration nor sleep duration range was significantly associated with quality of life in cross-sectional models.

    “Neither bad night sleep duration, nor sleep duration range, were significantly associated with depression or quality of life in these cross-sectional models.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    Neither bad night sleep duration nor sleep duration range was significantly associated with depression in cross-sectional models.

    “Neither bad night sleep duration, nor sleep duration range, were significantly associated with depression or quality of life in these cross-sectional models.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    Participants who received the cognitive therapy intervention showed more improvement in sleep over the study period, as well as significantly less severe psychotic experiences.

    “It is also worth noting that participants who received the cognitive therapy intervention showed more improvement in sleep over the study period (as well as significantly less severe psychotic experiences).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    Both study groups showed improvements in severity of psychotic experiences and other measures over time.

    “Indeed, as can be seen in the descriptive measures both study groups showed improvements in severity of psychotic experiences and other measures over time.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Between 37% and 78% of individuals at risk of psychosis report sleep disturbance, as assessed on the Scale of Assessment of Positive Symptoms (SAPS).

    “Between 37% and 78% of this population have been found to report sleep disturbance, as assessed on the Scale of Assessment of Positive Symptoms (SAPS) across several studies (Miller et al., 2003; Poe et al., 2017).”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites Miller et al., 2003 source

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    • cites Poe et al., 2017 source

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  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation

    Sleep disorders are common and severe, but treatable, among individuals with psychotic disorders.

    “Sleep disorders have also been shown to be common and severe, but treatable, among individuals with psychotic disorders (Freeman et al., 2009, Freeman et al., 2015).”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites Freeman et al., 2009 source

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    • cites Freeman et al., 2015 source

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  • Classified as probably not a substantial claim.

    Premisecitation

    Reducing sleep increases psychotic experiences.

    “It has been demonstrated that reducing sleep increases psychotic experiences (Reeve et al., 2018)”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites Reeve et al., 2018

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  • Classified as probably not a substantial claim.

    Premisecitation

    Treating insomnia improves psychotic experiences.

    “treating insomnia improves psychotic experiences (Freeman et al., 2017)”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites Freeman et al., 2017 source

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  • Classified as probably not a substantial claim.

    Premisecitation

    A causal role for sleep disturbance in contributing to psychotic experiences has recently begun to emerge.

    “A causal role for sleep disturbance in contributing to psychotic experiences has recently begun to emerge (Reeve et al., 2015).”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites Reeve et al., 2015 source

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  • May combine two claims.

    Premisereasoning

    The EDIE-2 dataset has the most assessment time points, and longest follow up period, of any study recording sleep in the at-risk population to date.

    “As study assessments were carried out every three months for a minimum of 12 months (and up to 24 months), the EDIE-2 dataset has the most assessment time points, and longest follow up period, of any study recording sleep in the at-risk population to date.”
    Quote in the paperSubstantial claim

  • The quote only partly states this claim.

    Study design and conductreasoning

    The final sample for the current study was 160 individuals after excluding participants from Birmingham and Cambridge sites and those without both good and bad sleep duration data.

    “This resulted in a final sample of 160 individuals for the current study.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductnone given

    Site and treatment allocation were included as factors in all models.

    “Site and treatment allocation were included as factors in all models.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Premisecitation

    Paranoia, hallucinations, grandiosity, and cognitive disorganisation exist as independent continua in the population with somewhat differing risk, development, and maintenance factors.

    “multiple sources of evidence indicate that paranoia, hallucinations, grandiosity, and cognitive disorganisation exist as independent continua in the population with somewhat differing risk, development, and maintenance factors (Ronald, 2015; van Os, 2014; Zavos et al., 2014).”
    Quote in the paperSubstantial claim0 of 3 sources checked
    • cites Ronald, 2015 source

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  • Classified as probably not a substantial claim. May combine two claims.

    Premisecitation

    Sleep loss affects dimensions of psychotic experience differently, with significant effects on hallucinations, paranoia, and cognitive disorganisation, but no effect on grandiosity.

    “sleep loss affects the dimensions of psychotic experience differently, with significant effects on hallucinations, paranoia, and cognitive disorganisation, but no effect on grandiosity (Reeve et al., 2018).”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites Reeve et al., 2018

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  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation

    The cognitive therapy based intervention plus monitoring was significantly better than monitoring only in reducing severity of psychotic experiences, but not in reducing distress or transition to psychosis over 12 to 24 months.

    “The cognitive therapy based intervention plus monitoring was significantly better than monitoring only in reducing severity of psychotic experiences, but not in reducing distress or transition to psychosis over 12 to 24 months (Morrison et al., 2012).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Morrison et al., 2012 source

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  • Classified as probably not a substantial claim.

    Study design and conductnone given

    The primary analysis approach was to run a set of pre-specified stepped linear mixed effects models to address each of the study hypotheses.

    “The primary analysis approach was to run a set of pre-specified stepped linear mixed effects models to address each of the study hypotheses, as listed below.”
    Quote in the paperSubstantial claim

  • Classified as probably not a substantial claim.

    Premisecitation

    Reporting sleep disturbance is highly predictive of transition to psychotic episode in the following 18 month period.

    “Reporting sleep disturbance has also been found to be highly predictive of transition to psychotic episode in the following 18 month period (Ruhrmann et al., 2010).”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites Ruhrmann et al., 2010 source

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  • Classified as probably not a substantial claim.

    Premisecitation

    EDIE-2 was a multi-site randomised controlled trial of a psychological intervention aiming to reduce transition to psychosis.

    “EDIE-2 was a multi-site randomised controlled trial of a psychological intervention aiming to reduce transition to psychosis (Morrison et al., 2011, Morrison et al., 2012).”
    Quote in the paperSubstantial claim0 of 2 sources checked
    • cites Morrison et al., 2011 source

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    • cites Morrison et al., 2012 source

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  • May combine two claims.

    Premisecitation

    Sleep recording studies have identified longer sleep onset latency, reduced sleep efficiency, and increased circadian rhythm disturbance in individuals at risk of psychosis compared to non-clinical controls.

    “sleep recording studies have identified a range of specific sleep abnormalities in individuals at-risk of psychosis, including longer sleep onset latency, reduced sleep efficiency, and increased circadian rhythm disturbance in comparison to non-clinical controls (Lunsford-Avery et al., 2015; Zanini et al., 2015).”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites Lunsford-Avery et al., 2015 source

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    • cites Zanini et al., 2015 source

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  • Classified as probably not a substantial claim.

    Premisecitation

    Objective sleep disturbances are linked with increased positive symptoms both at baseline and at 12 month follow up.

    “These objective sleep disturbances have been linked with increased positive symptoms both at baseline and at 12 month follow up (Lunsford-Avery et al., 2015, Lunsford-Avery et al., 2016).”
    Quote in the paperSubstantial claim0 of 2 sources checked
    • cites Lunsford-Avery et al., 2015 source

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    • cites Lunsford-Avery et al., 2016

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  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Study design and conductown data

    The study group was balanced between interventions, with 80 participants in each group.

    “The study group was balanced between interventions (n = 80, 50%, in each group).”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S2 (checkable), S3 (load-bearing).

    Interpretationcitation

    These findings are consistent with theoretical models for sleep disruption and psychosis in the at-risk group.

    “These findings are consistent with theoretical models for sleep disruption and psychosis in the at-risk group.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Lunsford-Avery and Mittal, 2013

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  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Fatigue is more linked than sleep to functional health (Waters et al., 2013).

    “A potential explanation could be that fatigue is more linked than sleep to functional health (Waters et al., 2013), however as there was no measure of fatigue in the current study it was not possible to assess this.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Waters et al., 2013

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  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation

    Sleep problems reduce quality of life (Kyle et al., 2010a, Kyle et al., 2010b), and sleep and quality of life have both been linked to psychotic symptoms in clinical groups (Afonso et al., 2011).

    “Sleep problems reduce quality of life (Kyle et al., 2010a, Kyle et al., 2010b), and sleep and quality of life have both been linked to psychotic symptoms in clinical groups (Afonso et al., 2011).”
    Quote in the paperNot a substantial claim0 of 3 sources checked
    • cites Kyle et al., 2010a

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    • cites Kyle et al., 2010b

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    • cites Afonso et al., 2011 source

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  • May combine two claims.

    Interpretationown data

    Previous psychotic experience is a stronger predictor than previous sleep disturbance for later psychotic experiences, with no evidence of a unique contribution of sleep disturbance across time for predicting change in psychotic experiences.

    “This final set of models therefore suggest that previous psychotic experience is a stronger predictor than previous sleep disturbance for later psychotic experiences, with no evidence of a unique contribution of sleep disturbance across time for predicting change in psychotic experiences.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationcitation

    The association between narrower range and increased psychotic experiences was contrary to the study hypothesis and appears inconsistent with previous studies that have reported a link between increased sleep variability and psychotic experiences (Lunsford-Avery et al., 2016; Waters et al., 2011).

    “The association between narrower range and increased psychotic experiences was contrary to the study hypothesis, and appears inconsistent with previous studies that have reported a link between increased sleep variability and psychotic experiences (Lunsford-Avery et al., 2016; Waters et al., 2011).”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites Lunsford-Avery et al., 2016

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    • cites Waters et al., 2011 source

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    Premisecitation

    Sleep disturbances are thought to initiate a vicious cycle wherein disrupted sleep leads to increased psychotic experiences, the distress from which disrupts sleep further.

    “In other words, sleep disturbances are thought to initiate a vicious cycle wherein disrupted sleep leads to increased psychotic experiences, the distress from which disrupts sleep further (Lunsford-Avery and Mittal, 2013).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Lunsford-Avery and Mittal, 2013

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    Premisecitation

    In one model, sleep/wake disturbances are seen as both reflecting an underlying biological vulnerability and as an additional stressor.

    “In one model sleep/wake disturbances are seen as both reflecting an underlying biological vulnerability and as an additional stressor.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
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    Premisecitation

    A recent pilot case series with an at-risk population indicated that treating sleep problems did result in decreases in psychotic experiences and negative affect (Bradley et al., 2018).

    “A recent pilot case series with an at-risk population indicated that treating sleep problems did result in decreases in psychotic experiences and negative affect (Bradley et al., 2018).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Bradley et al., 2018 source

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  • May combine two claims.

    Interpretationown data

    The non-significant relationship between depression and either measure of sleep disturbance is contrary to previous findings indicating negative affect as a mediator in the sleep disturbance and psychosis relationship (e.g. Reeve et al., 2018), and contrary to a general literature linking sleep disturbance with depression (Murphy and Peterson, 2015).

    “This is contrary to previous findings indicating negative affect as a mediator in the sleep disturbance and psychosis relationship (e.g. Reeve et al., 2018), and contrary to a general literature linking sleep disturbance with depression (Murphy and Peterson, 2015).”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites Reeve et al., 2018

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    • cites Murphy and Peterson, 2015

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  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Interpretationown data

    The null finding in both depression and quality of life could be related to lower power in these tests, given the lower rate of completion of these measures.

    “The null finding in both depression and quality of life could also be related to lower power in these tests, given the lower rate of completion of these measures.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Interpretationreasoning

    Co-linearity decreases the possibility that individual variables will emerge as predictors of variance in the outcome (i.e. psychotic experience severity).

    “This decreases the possibility that individual variables will emerge as predictors of variance in the outcome (i.e. psychotic experience severity).”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Interpretationreasoning

    This may have contributed to the low significance of the relationships reported, which in many cases would not survive conservative corrections for multiple testing.

    “This may have contributed to the low significance of the relationships reported, which in many cases would not survive conservative corrections for multiple testing.”
    Quote in the paperNot a substantial claim

  • Classified as probably not a substantial claim.

    Interpretationreasoning

    This study supports the potential importance of treating sleep disturbance in this group.

    “This study also supports the potential importance of treating sleep disturbance in this group, a possibility now beginning to be explored in the clinical literature (Bradley et al., 2018).”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites Bradley et al., 2018 source

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  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Youth at risk of psychosis have elsewhere been found to be accurate self-reporters of sleep duration (Lunsford-Avery et al., 2015).

    “It is also worth noting that youth at risk of psychosis have elsewhere been found to be accurate self-reporters of sleep duration (Lunsford-Avery et al., 2015).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
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    Interpretationown data

    The transition rate could have been lower due to a positive effect of the study monitoring on improving psychotic experiences.

    “This transition rate could have been lower due to a positive effect of the study monitoring on improving psychotic experiences.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Study design and conductown data

    The frequency of good nights versus bad nights was not assessed, which would have allowed calculation of an average sleep time and variability of sleep.

    “For example, the frequency of good nights versus bad nights was not assessed, which would have allowed calculation of an average sleep time and variability of sleep.”
    Quote in the paperNot a substantial claim

  • Classified as probably not a substantial claim.

    Study design and conductcitation

    Given that the approach here is of planned comparisons, where all analyses are pre-specified, it is not necessarily appropriate to apply corrections for multiple testing (Feise, 2002; Schulz and Grimes, 2005).

    “However, given that the approach here is of planned comparisons, where all analyses are pre-specified, it is not necessarily appropriate to apply these corrections (Feise, 2002; Schulz and Grimes, 2005).”
    Quote in the paperSubstantial claim0 of 2 sources checked
    • cites Feise, 2002 source

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    Study design and conductnone given

    Substance abuse was not accounted for in the current study.

    “Substance abuse was also not accounted for in the current study.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Study design and conductnone given

    It was not possible to control for age or occupational status, which are likely to be a source of significant variance in sleep as reported in the current study.

    “Furthermore, it was not possible to control for age or occupational status, which are likely to be a source of significant variance in sleep as reported in the current study.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Circadian dysfunction is commonly reported in individuals with psychosis (Wulff et al., 2012).

    “The duration variable also does not give context on the timing of sleep, which is important as circadian dysfunction is commonly reported in individuals with psychosis (Wulff et al., 2012), and has been found to be predictive of positive symptoms in individuals at risk of psychosis (Lunsford-Avery et al., 2016).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Wulff et al., 2012 source

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  • Classified as probably not a substantial claim. May combine two claims.

    Interpretationreasoning

    In the present study, differences between the starting position for each participant is non-arbitrary, therefore mean centering was not appropriate.

    “However, in the present study differences between the starting position for each participant is non-arbitrary (e.g. a change from 8 h to 6 h sleep on a bad night is unlikely to have the same effect as a change from 6 h to 4 h), therefore this option was not appropriate.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Circadian dysfunction has been found to be predictive of positive symptoms in individuals at risk of psychosis (Lunsford-Avery et al., 2016).

    “The duration variable also does not give context on the timing of sleep, which is important as circadian dysfunction is commonly reported in individuals with psychosis (Wulff et al., 2012), and has been found to be predictive of positive symptoms in individuals at risk of psychosis (Lunsford-Avery et al., 2016).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Lunsford-Avery et al., 2016

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  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductreasoning

    The duration variable does not give context on the timing of sleep.

    “The duration variable also does not give context on the timing of sleep, which is important as circadian dysfunction is commonly reported in individuals with psychosis (Wulff et al., 2012), and has been found to be predictive of positive symptoms in individuals at risk of psychosis (Lunsford-Avery et al., 2016).”
    Quote in the paperNot a substantial claim

  • Classified as probably not a substantial claim.

    Study design and conductown data

    The sleep information in the current study is not a single sleep quality judgement as in the SAPS, but gives duration information.

    “However, one advantage of the current study is that the sleep information is not a single sleep quality judgement as in the SAPS, but gives duration information.”
    Quote in the paperSubstantial claim
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  • The authors state this as an assumption.

    Data are missing at random.

    “allow use of all available data under the assumption that data are missing at random.”

  • The authors state this as an assumption.

    Shorter bad night sleep duration and larger range of sleep duration indicate secondary aspects of sleep disturbance from sleep disorders.

    “The expectation is that a shorter bad night sleep duration and larger range of sleep duration suggest secondary aspects of sleep disturbance from sleep disorders.”

  • The paper relies on this without support.

    The BDI-PC scale is typically used as a screening tool with a categorical outcome, with scores ≥4 indicating major depression.

    “The BDI-PC scale used in the current study is typically used as a screening tool with a categorical outcome (with scores ≥4 indicating major depression).”
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Percentages, sums and reported differences re-computed from the paper’s own numbers.

Each contradiction between two passages listed here was confirmed by an independent check.

  • Mean age differs between text and Table 1

    Minor

    The demographic text gives a mean age of 20.7 years, while Table 1 gives 20.9 years for the study group.

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Authors
Reeve, S., Nickless, A., Sheaves, B., Hodgekins, J., Stewart, S. L. K., Gumley, A., Fowler, D., Morrison, A., & Freeman, D.
Affiliations
  • Warneford Hospital (GB)
  • University of Oxford (GB)
  • Oxford Health NHS Foundation Trust (GB)
  • University of East Anglia (GB)
  • University of Chester (GB)
  • Gartnavel General Hospital (GB)
  • University of Sussex (GB)
  • University of Manchester (GB)
Corresponding author
Reeve, S.
ORCID
Venue
Schizophrenia Research
Publisher
Elsevier BV
Published
2019-02
Volume
204
Pages
326-333
ISSN
0920-9964 (ISSN-L)
DOI
10.1016/j.schres.2018.08.006
PMC
PMC6406020
OpenAlex
W2885840302
Cited by
39
References
40
Citations by year
2026: 2 · 2025: 2 · 2024: 7 · 2023: 6 · 2022: 5 · 2021: 9 · 2020: 5 · 2019: 3
FWCI
3.32
Type
journal article
Language
en
Open access
Licence
Locations
  • Schizophrenia Research (publishedVersion, cc-by)
  • Europe PMC (PubMed Central) (publishedVersion, cc-by)
  • PubMed Central (publishedVersion, cc-by)
  • PubMed (publishedVersion)
  • Research Explorer (The University of Manchester) (publishedVersion, cc-by)
  • UEA Digital Repository (University of East Anglia) (acceptedVersion)
  • Explore Bristol Research (submittedVersion, cc-by)
  • ChesterRep (University of Chester) (submittedVersion, cc-by-nc-nd)
  • ChesterRep (University of Chester) (submittedVersion)
Funders
  • Medical Research Council (G0500264)
  • Department of Health
  • Medical Research Council Doctoral Studentship
  • Balliol College
  • University of Oxford
  • Wellcome Trust (098461/Z/12/Z)
  • National Institute of Health Research (RP-2014-05-003)
Topics
  • Health Sciences › Medicine › Psychiatry and Mental health › Schizophrenia research and treatment
  • Social Sciences › Psychology › Experimental and Cognitive Psychology › Sleep and related disorders
  • Life Sciences › Neuroscience › Cognitive Neuroscience › Sleep and Wakefulness Research
Keywords
sleep duration, sleep disorders
MeSH terms
Adolescent, Adult, Cross-Sectional Studies, Delusions, Female, Hallucinations, Humans, Longitudinal Studies, Male, Psychotic Disorders, Risk, Sleep, Sleep Wake Disorders, Comorbidity, Early Diagnosis, Young Adult, Early Medical Intervention

About these checks

Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.

Claims read by deepseek-v4.1-flash under definition version 3 (extract-v3) on 2026-10-09.

Classified by jev-1.13-20260917 (gold-guideline-v0.2) on 2026-10-09.

Statistics and arithmetic are recomputed, not judged.

Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.

What counts as a claim ›How we measure confidence ›How we check this ›

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