Cognitive behaviour therapy for schizophrenia

Medication is the mainstay of treatment for schizophrenia. Many people with schizophrenia, however, continue to experience symptoms in spite of medication and may experience side effects that are unwanted and unpleasant. In addition to medication additional forms of treatment include talking therapies such as cognitive behavioural therapy. This approach helps to link the person's feelings and patterns of thinking which underpin distress.

To review the effectiveness of cognitive behavioural therapy for people with schizophrenia, when compared to standard care, specific medication, other therapies and non-intervention.

Electronic searches of Biological Abstracts (1980-1998), CINAHL (1982-1998), The Cochrane Library (Issue 2, 1998), The Cochrane Schizophrenia Groups' Register of Trials, which encompasses up to date searches of all listed databases (January 2001), EMBASE (1980-1998), MEDLINE (1966-1998), PsychLIT (1887-1997), SIGLE (1990-1998), Sociofile (1980-1998) were undertaken. All references of the articles selected were searched for further relevant trials.

This review includes relevant randomised trials of cognitive behaviour therapy for people with a diagnosis of schizophrenia-like illnesses. Outcomes such as death, mental state, relapse, psychological well-being and acceptability of treatment were sought.

Studies were reliably selected and assessed for methodological quality. Data were extracted by two reviewers working independently. Dichotomous data were analysed on an intention-to-treat basis and continuous data with 65% completion rate are presented. Where possible, for dichotomous outcomes, a relative risk (RR) with the 95% confidence interval (CI) was estimated along with the number needed to treat statistic (NNT).

Twenty-two relevant papers describing thirteen trials were identified. Cognitive behavioural therapy in addition to standard care did not significantly reduce the rate of relapse and readmission to hospital when compared with standard care alone (medium term 1 RCT, N=61, RR 0.1 CI 0.01 to 1.7; long term 2 RCTs, N=123, RR 1.1 CI 0.8 to 1.5). A significant difference was observed, however, favouring cognitive behavioural therapy over standard care alone, in terms of being able to be discharged from hospital (1 RCT, N=62, RR 0.5 CI 0.3 to 0.9, NNT 3 CI 2 to 12). For 'no important improvement in mental state' data showed a significant difference favouring the cognitive behavioural therapy group over standard care alone when measured at 13 to 26 weeks (2 RCTs, N=123, RR 0.7 CI 0.6 to 0.9, NNT 4 CI 2 to 8). After one year the difference was no longer significant (3 RCTs, N=211, RR 0.95 CI 0.6 to 1.5). On continuous measures (BPRS, CPRS, Psychiatric Assessment Scale) data are not convincing of an effect. A cognitive behavioural therapy approach focusing on compliance may have some effects on insight and attitudes to medication, but the clinical meaning of these data is unclear. When compared with supportive psychotherapy, cognitive behavioural therapy had no effects on relapse rate and clinically meaningful improvements in mental state. Cognitive behavioural therapy combined with other psycho-social/educational interventions may decrease the numbers of people able to tolerate the intervention, at least under study conditions.

Cognitive behavioural therapy is a promising but under evaluated intervention. Currently, trial-based data supporting the wide use of cognitive behavioural therapy 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.