Background: Cognitive behavioural therapy (CBT) is now a recommended treatment for people with schizophrenia. This approach helps to link the person's feelings and patterns of thinking which underpin distress.
Objectives: To review the effects of CBT for people with schizophrenia when compared to standard care, specific medication, other therapies and no intervention.
Search strategy: This 2004 update built on past work by searching the Cochrane Schizophrenia Groups' Register of Trials (January 2004). We inspected all references of the selected articles for further relevant trials.
Selection criteria: All relevant clinical randomised trials of cognitive behaviour therapy for people with schizophrenia-like illnesses.
Data collection and analysis: Studies were reliably selected and assessed for methodological quality. Two reviewers, 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 relative risk (RR) with the 95% confidence interval (CI) along with the number needed to treat/harm (NNT/H).
Main results: 30 papers described 19 trials. CBT plus standard care did not reduce relapse and readmission compared with standard care (long term 4 RCTs, n=357, RR 0.8 CI 0.5 to 1.5), but did decrease the risk of staying in hospital (1 RCT, n=62, RR 0.5 CI 0.3 to 0.9, NNT 4 CI 3 to 15). CBT helped mental state over the medium term (2 RCTs, n=123, RR No meaningful improvement 0.7 CI 0.6 to 0.9, NNT 4 CI 3 to 9) but after one year the difference was gone (3 RCTs, n=211, RR 0.95 CI 0.6 to 1.5). Continuous measures of mental state (BDI, BPRS, CPRS, MADRS, PAS) do not demonstrate a consistent effect. When compared with supportive psychotherapy, CBT had no effect on relapse (1 RCT, n=59, RR medium term 0.6 CI 0.2 to 2; 2 RCTs, n=83, RR long term 1.1 CI 0.5 to 2.4). This also applies to the outcome of 'No clinically meaningful improvements in mental state' over the same time periods (1 RCT, n=59, RR medium term 0.8 CI 0.6 to 1.1; 2 RCT, n=100, RR long term 0.9 CI 0.8 to 1.1). When CBT was combined with a psychoeducational approach there was no significant reduction of readmission rates relative to standard care alone (1 RCT, n=91, RR 0.9 CI 0.6 to 1.4).
Reviewers' conclusions: CBT is a promising but under evaluated intervention. Currently, trial-based data supporting the wide use of CBT for people with schizophrenia or other psychotic illnesses are far from conclusive. More trials are justified, especially in comparison with a lower grade supportive approach. These trials should be designed to be both clinically meaningful and widely applicable.