The effect of cognitive behavioral treatment on the positive symptoms of schizophrenia spectrum disorders: a meta-analysis

BACKGROUND: Despite the effectiveness of anti-psychotic pharmacotherapy, residual hallucinations and delusions do not completely resolve in some medicated patients. Additional cognitive behavioral therapy (CBT) seems to improve the management of positive symptoms. Despite promising results, the efficacy of CBT is still unclear. The present study addresses this issue taking into account a number of newly published controlled studies. METHOD: Fourteen studies including 1484 patients, published between 1990 and 2004 were identified and a meta-analysis of their results performed. RESULTS: Compared to other adjunctive measures, CBT showed significant reduction in positive symptoms and there was a higher benefit of CBT for patients suffering an acute psychotic episode versus the chronic condition (effect size of 0.57 vs. 0.27). DISCUSSION: CBT is a promising adjunctive treatment for positive symptoms in schizophrenia spectrum disorders. However, a number of potentially modifying variables have not yet been examined, such as therapeutic alliance and neuropsychological deficits.