A systematic review examining factors predicting favourable outcome in cognitive behavioural interventions for psychosis

Psychosis is a debilitating mental health condition affecting approximately 4 persons per 1000. Cognitive behavioural therapy for psychosis (CBTp) has been shown to be an effective treatment for psychosis and is recommended by several national guidelines. CBTp does not work equally well with everyone, however, with some 50% of clients receiving little benefit. This review sets out to systematically assess the literature and methodological quality of a number of studies, which examine factors predicting successful outcome in CBTp. The databases CINAHL, Cochrane, EBSCO, EMBASE, ISI Web of Science, MEDLINE (Ovid), PsycARTICLES, PsycINFO, PubMed, and Scopus were electronically searched. English language articles in peer reviewed journals were reviewed. Search terms “psychosis”, “psychotic disorder”, “cognitive behavioural therapy”, “cognitive therapy”, “randomised controlled trial”, “predictor”, and “treatment outcome” in various combinations were used as needed. Only randomised controlled trials (RCTs) were included. Results suggest that female gender, older age, and higher clinical insight at baseline, each predicted better outcome in CBT interventions with psychotic patients, as did a shorter duration of the illness, and higher educational attainment. Several other factors, such as higher symptom severity at baseline, were suggestive of predictive capacity but further research to clarify was indicated. Providers of mental healthcare should consider these findings when offering CBTp. The onus is also on healthcare providers to better equip non-responders to CBTp. Further investigation into a limited number of predictive factors, with an agreed set of outcome measures, would allow future researchers more direct comparisons between studies.