Background: Research evidence supports the efficacy of cognitive-behavioral therapy in the treatment of drug-refractory positive symptoms of schizophrenia. Although the cumulative evidence is strong, early controlled trials showed methodological limitations.
Methods: A randomized controlled design was used to compare the efficacy of manualized cognitive-behavioral therapy developed particularly for schizophrenia with that of a nonspecific befriending control intervention. Both interventions were delivered by 2 experienced nurses who received regular supervision. Patients were assessed by blind raters at baseline, after treatment (lasting up to 9 months), and at a 9-month follow-up evaluation. Patients continued to receive routine care throughout the study. An assessor blind to the patients' treatment groups rated the technical quality of audiotaped sessions chosen at random. Analysis was by intention to treat.
Results: Ninety patients received a mean of 19 individual treatment sessions over 9 months, with no significant between-group differences in treatment duration. Both interventions resulted in significant reductions in positive and negative symptoms and depression. At the 9-month follow-up evaluation, patients who had received cognitive therapy continued to improve, while those in the befriending group did not. These results were not attributable to changes in prescribed medication.
Conclusion: Cognitive-behavioral therapy is effective in treating negative as well as positive symptoms in schizophrenia resistant to standard antipsychotic drugs, with its efficacy sustained over 9 months of follow-up.