title: Effects of cognitive behavioural therapy for insomnia on the mental health of university students: study protocol for a randomized controlled trial.
abstract: BACKGROUND
  Insomnia, defined as repeated difficulties getting or staying asleep, is common in the general population. Such sleep difficulties are a problem in their own right, but increasingly it is being recognised that they may also be a contributory factor in the development of a wide range of mental health problems. Our focus is upon the relationship between insomnia and psychotic experiences, such as paranoia and hallucinations. Psychotic experiences commonly occur in mild forms in the general population and have been linked to disrupted sleep. These psychotic-like experiences raise the risk of development of a clinical disorder. Our aim is to reduce insomnia in a large general population group, and examine the effect on paranoia and hallucinations at the age when mental health problems typically emerge. The primary hypotheses are that cognitive behaviour therapy (CBT) for insomnia will reduce insomnia and also levels of paranoia and hallucinations. The theoretical links will be substantiated by a planned mediation analysis. Improvements in a number of other mental health outcomes are also predicted.
  
  
  METHODS
  We will carry out a parallel group, randomised controlled trial of 2,614 students with insomnia in universities across the UK. In the Oxford Access for Students Improving Sleep (OASIS) trial, participants will be randomised to digital CBT for insomnia (in addition to treatment as usual) or treatment as usual. Online assessments will take place at zero, three, 10 (post-treatment), and 22 (follow-up) weeks. Primary outcomes are insomnia and psychotic-like experiences (paranoia or hallucinatory experiences) at 10 weeks. Secondary outcomes are levels of mania, depression, anxiety, nightmares, psychological wellbeing, and the development of mental health disorders. All main analyses will be carried out at the end of the last follow-up assessment and will be based on the intention-to-treat principle. The trial is funded by the Wellcome Trust.
  
  
  CONCLUSIONS
  This study will be the first large-scale causal test of the relationship between sleep disturbance and psychotic experiences. It will provide evidence concerning the clinical effects of treating insomnia in young adults.
  
  
  BACKGROUND
  This trial was registered with Current Controlled Trials (identifier: ISRCTN61272251 ) on 29 January 2015.
authors.affiliation: Sleep & Circadian Neuroscience Institute, Department of Psychiatry, University of Oxford, Warneford Hospital, Warneford Lane, Oxford, OX3 7JX, UK. daniel.freeman@psych.ox.ac.uk.
authors.forename: Daniel
authors.initials: D
authors.lastname: Freeman
authors.affiliation: Sleep & Circadian Neuroscience Institute, Department of Psychiatry, University of Oxford, Warneford Hospital, Warneford Lane, Oxford, OX3 7JX, UK. bryony.sheaves@psych.ox.ac.uk.
authors.forename: Bryony
authors.initials: B
authors.lastname: Sheaves
authors.affiliation: Sleep & Circadian Neuroscience Institute, Department of Psychiatry, University of Oxford, Warneford Hospital, Warneford Lane, Oxford, OX3 7JX, UK. guy.goodwin@psych.ox.ac.uk.
authors.forename: Guy M
authors.initials: GM
authors.lastname: Goodwin
authors.affiliation: Nuffield Department of Primary Care Health Sciences, University of Oxford, Gibson Building 1st Floor, Radcliffe Observatory Quarter, Woodstock Road, Oxford, OX2 6GG, UK. ly-mee.yu@phc.ox.ac.uk.
authors.forename: Ly-Mee
authors.initials: LM
authors.lastname: Yu
authors.affiliation: Sleep & Circadian Neuroscience Institute, Department of Psychiatry, University of Oxford, Warneford Hospital, Warneford Lane, Oxford, OX3 7JX, UK. Paul.harrison@psych.ox.ac.uk.
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Harrison
authors.affiliation: Centre for Biostatistics, Institute of Population Health, The University of Manchester, Manchester Academic Health Science Centre, 1.304 Jean McFarlane Building, Oxford Road, Manchester, M13 9PL, UK. Richard.Emsley@manchester.ac.uk.
authors.forename: Richard
authors.initials: R
authors.lastname: Emsley
authors.affiliation: Sleepio Ltd, 60-62 Commercial Street, London, E1 6LT, UK. Sophie@sleepio.com.
authors.forename: Sophie
authors.initials: S
authors.lastname: Bostock
authors.affiliation: Sleep & Circadian Neuroscience Institute, Nuffield Department of Clinical Neurosciences, University of Oxford, Level 5-6 West Wing, John Radcliffe Hospital, Oxford, OX3 9DU, UK. russell.foster@eye.ox.ac.uk.
authors.forename: Russell G
authors.initials: RG
authors.lastname: Foster
authors.affiliation: Department of Psychiatry, University of Oxford, Warneford Hospital, Warneford Lane, Oxford, OX3 7JX, UK. vanashree.wadekar@psych.ox.ac.uk.
authors.forename: Vanashree
authors.initials: V
authors.lastname: Wadekar
authors.affiliation: Department of Psychiatry, University of Oxford, Warneford Hospital, Warneford Lane, Oxford, OX3 7JX, UK. Chris.hinds@psych.ox.ac.uk.
authors.forename: Christopher
authors.initials: C
authors.lastname: Hinds
authors.affiliation: Sleepio Ltd, 60-62 Commercial Street, London, E1 6LT, UK. colin.espie@ndcn.ox.ac.uk.|Sleep & Circadian Neuroscience Institute, Nuffield Department of Clinical Neurosciences, University of Oxford, Level 5-6 West Wing, John Radcliffe Hospital, Oxford, OX3 9DU, UK. colin.espie@ndcn.ox.ac.uk.
authors.forename: Colin A
authors.initials: CA
authors.lastname: Espie
mesh_terms: D000293:Adolescent; D000328:Adult; D005260:Female; D006801:Humans; D008297:Male; D055815:Young Adult; D015928:Cognitive Behavioral Therapy; D006212:Hallucinations / Q000517:prevention & control / Q000523:psychology; D057194:Intention to Treat Analysis; D008603:Mental Health; D010258:Paranoid Behavior; D010259:Paranoid Disorders / Q000517:prevention & control / Q000523:psychology; D011569:Psychiatric Status Rating Scales; D012107:Research Design; D016037:Single-Blind Method; D012890:Sleep; D007319:Sleep Initiation and Maintenance Disorders / Q000175:diagnosis / Q000523:psychology / Q000628:therapy; D013334:Students / Q000523:psychology; D013997:Time Factors; D016896:Treatment Outcome; D006113:United Kingdom; D014495:Universities; D016032:Randomized Controlled Trials as Topic; D015337:Multicenter Studies as Topic