Background. Although cognitive behavioural therapy (CBT) is claimed to be effective in schizophrenia, major depression and bipolar disorder, there have been negative findings in well-conducted studies and meta-analyses have not fully considered the potential influence of blindness or the use of control interventions.Method. We pooled data from published trials of CBT in schizophrenia, major depression and bipolar disorder that used controls for non-specific effects of intervention. Trials of effectiveness against relapse were also pooled, including those that compared CBT to treatment as usual (TAU). Blinding was examined as a moderating factor.Results. CBT was not effective in reducing symptoms in schizophrenia or in preventing relapse. CBT was effective in reducing symptoms in major depression, although the effect size was small, and in reducing relapse. CBT was ineffective in reducing relapse in bipolar disorder.Conclusions. CBT is no better than non-specific control interventions in the treatment of schizophrenia and does not reduce relapse rates. It is effective in major depression but the size of the effect is small in treatment studies. On present evidence CBT is not an effective treatment strategy for prevention of relapse in bipolar disorder. Key words : Bipolar disorder, cognitive therapy, depression, schizophrenia.
IntroductionCognitive behavioural therapy (CBT) has been widely adopted by psychiatry in recent years, but its increase in use in the severe disorders of schizophrenia, major depression and bipolar disorder is particularly noteworthy. This is because it challenges what has, until recently, been a dominance of biological approaches to these disorders. Thus, although contemporary accounts of schizophrenia (e.g. Picchioni & Murray, 2007) emphasize biological factors in its aetiology and consider neuroleptic drugs to be the mainstay of treatment, official UK treatment guidelines from the National Institute for Clinical Excellence (NICE) also state that psychological interventions are indispensable and that CBT should be offered to all patients (NICE, 2003(NICE, , 2009. Psychological factors may loom larger in the aetiology of major affective disorder, but when it comes to treatment, the emphasis in the literature, particularly in bipolar disorder, has once again been firmly on pharmacotherapy. Attitudes may be changing here too, however. References to the effectiveness of CBT are pervasive in the UK depression treatment guideline (NICE, 2004) ; a government initiative is under way in the UK to provide CBT for depression and anxiety in 250 dedicated therapy centres (Layard, 2006) ; and CBT is being advocated for relapse prevention in bipolar disorder (e.g. Scott & Colom, 2005 ;Basco & Rush, 2007).Nevertheless, a cursory look at the literature reveals well-conducted trials where CBT has had negative findings in all three disorders. For example, large-scale trials of CBT in schizophrenia have failed to find significant advantages over befriending (Sensky et al. 2000) or supportive counselling (L...