Cognitive behavioural therapy (CBT) is now a recommended treatment for people with schizophrenia. This approach helps to link the person's distress and problem behaviours to underlying patterns of thinking.
To review the effects of CBT for people with schizophrenia when compared with other psychological therapies.
We searched the Cochrane Schizophrenia Group Trials Register (March 2010) which is based on regular searches of CINAHL, EMBASE, MEDLINE and PsycINFO. We inspected all references of the selected articles for further relevant trials, and, where appropriate, contacted authors.
All relevant randomised controlled trials (RCTs) of CBT for people with schizophrenia-like illnesses.
Studies were reliably selected and assessed for methodological quality. Two review authors, working independently, extracted data. We analysed dichotomous data on an intention-to-treat basis and continuous data with 65% completion rate are presented. Where possible, for dichotomous outcomes, we estimated a risk ratio (RR) with the 95% confidence interval (CI) along with the number needed to treat/harm.
Thirty papers described 20 trials. Trials were often small and of limited quality. When CBT was compared with other psychosocial therapies, no difference was found for outcomes relevant to adverse effect/events (2 RCTs, n = 202, RR death 0.57 CI 0.12 to 2.60). Relapse was not reduced over any time period (5 RCTs, n = 183, RR long-term 0.91 CI 0.63 to 1.32) nor was rehospitalisation (5 RCTs, n = 294, RR in longer term 0.86 CI 0.62 to 1.21). Various global mental state measures failed to show difference (4 RCTs, n = 244, RR no important change in mental state 0.84 CI 0.64 to 1.09). More specific measures of mental state failed to show differential effects on positive or negative symptoms of schizophrenia but there may be some longer term effect for affective symptoms (2 RCTs, n = 105, mean difference (MD) Beck Depression Inventory (BDI) -6.21 CI -10.81 to -1.61). Few trials report on social functioning or quality of life. Findings do not convincingly favour either of the interventions (2 RCTs, n = 103, MD Social Functioning Scale (SFS) 1.32 CI -4.90 to 7.54; n = 37, MD EuroQOL -1.86 CI -19.20 to 15.48). For the outcome of leaving the study early, we found no significant advantage when CBT was compared with either non-active control therapies (4 RCTs, n = 433, RR 0.88 CI 0.63 to 1.23) or active therapies (6 RCTs, n = 339, RR 0.75 CI 0.40 to 1.43)
Trial-based evidence suggests no clear and convincing advantage for cognitive behavioural therapy over other - and sometime much less sophisticated - therapies for people with schizophrenia.