Cognitive therapy for psychosis in schizophrenia: an effect size analysis.

We conducted a meta-analysis using all available controlled treatment outcome studies of cognitive therapy (CT) for psychotic symptoms in schizophrenia. Effect sizes were calculated for seven studies involving 340 subjects. The mean effect size for reduction of psychotic symptoms was 0.65. The findings suggest that cognitive therapy is an effective treatment for patients with schizophrenia who have persistent psychotic symptoms. Follow-up analyses in four studies indicated that patients receiving CT continued to make gains over time (ES=0.93). Further research is needed to determine the replicability of standardized cognitive interventions, to evaluate the clinical significance of cognitive therapy for schizophrenia, and to determine which patients are most likely to benefit from this intervention.