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Early interventions to prevent psychosis: systematic review and meta-analysis

BMJ 2013; 346 doi: (Published 18 January 2013) Cite this as: BMJ 2013;346:f185
  1. Megan R Stafford, systematic reviewer1,
  2. Hannah Jackson, research assistant1,
  3. Evan Mayo-Wilson, senior research associate2,
  4. Anthony P Morrison, professor of clinical psychology3,
  5. Tim Kendall, codirector National Collaborating Centre for Mental Health4
  1. 1National Collaborating Centre for Mental Health, Royal College of Psychiatrists, London, UK
  2. 2Centre for Outcomes Research and Effectiveness, Research Department of Clinical, Educational and Health Psychology, University College London, London, UK
  3. 3School of Psychological Sciences, University of Manchester, Manchester, UK
  4. 4Sheffield Health and Social Care NHS Foundation Trust, Sheffield S10 3TH, UK
  1. Correspondence to: T Kendall tim.kendall{at}
  • Accepted 8 January 2013


Objective To determine whether any psychological, pharmacological, or nutritional interventions can prevent or delay transition to psychotic disorders for people at high risk.

Design Systematic review and meta-analysis.

Data sources Embase, Medline, PreMedline, PsycINFO, and CENTRAL were searched to November 2011 without restriction to publication status.

Review methods Randomised trials comparing any psychological, pharmacological, nutritional, or combined intervention with usual services or another treatment. Studies of participants with a formal diagnosis of schizophrenia or bipolar disorder were excluded. Studies were assessed for bias, and relevant limitations were considered in summarising the results.

Results 11 trials including 1246 participants and eight comparisons were included. Median sample size of included trials was 81 (range 51-288). Meta-analyses were performed for transition to psychosis, symptoms of psychosis, depression, and mania; quality of life; weight; and discontinuation of treatment. Evidence of moderate quality showed an effect for cognitive behavioural therapy on reducing transition to psychosis at 12 months (risk ratio 0.54 (95% confidence interval 0.34 to 0.86); risk difference −0.07 (−0.14 to −0.01). Very low quality evidence for omega-3 fatty acids and low to very low quality evidence for integrated psychotherapy also indicated that these interventions were associated with reductions in transition to psychosis at 12 months.

Conclusions Although evidence of benefits for any specific intervention is not conclusive, these findings suggest that it might be possible to delay or prevent transition to psychosis. Further research should be undertaken to establish conclusively the potential for benefit of psychological interventions in the treatment of people at high risk of psychosis.


  • Contributors: All authors contributed to the development of the review questions. MS and EMW drafted the protocol. Sarah Stockton of the National Collaborating Centre for Mental Health) designed and implemented the searches. MS, HJ, and EMW assessed the eligibility of the studies for inclusion, extracted data, assessed risk of bias, and applied the GRADE criteria. All authors contributed to the analysis. All authors contributed to writing the manuscript, agreed on the final draft, had full access to the data (including statistical results and tables), and take responsibility for the integrity of the data and accuracy of the analysis. TK is the guarantor.

  • Funding: The National Collaborating Centre for Mental Health receives £1.4 million per year from the National Institute for Health and Clinical Excellence to develop guidelines for the treatment of mental health problems.

  • Competing interests: All authors have completed the Unified Competing Interest form at (available on request from the corresponding author) and declare: support from the National Institute for Health and Clinical Excellence for the submitted work; TK is codirector of the National Collaborating Centre for Mental Health; this work was conducted as part of a guideline about psychosis in children and young people, and the full review protocol is available from the authors; AM was an author of two studies included in this review.

  • Ethical approval: None required.

  • Data sharing: No additional data available.

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