Nefazodone in the adjunctive therapy of schizophrenia: An open-label exploratory study

Compared to conventional antipsychotic medications, atypical antipsychotic medications demonstrate greater central serotonin (5HT₂) receptor antagonism than dopamine type 2 (D₂) receptor antagonism. Nefazodone, an antidepressant medication, exhibits 5HT₂ receptor antagonism; we therefore wondered if its addition to stable regimens of antipsychotic medication would increase antipsychotic efficacy, independently of a primary effect on mood, through the mechanism of augmented 5HT₂ receptor antagonism. In a pilot investigation, we administered nefazodone (400 mg/d) for 6 weeks as an open-label adjunct to antipsychotic medication in 10 patients with chronic schizophrenia. The patients were moderately depressed at baseline but did not meet criteria for major depressive episode. The Brief Psychiatric Rating Scale (BPRS) and Montgomery-Asberg Depression Rating Scale scores showed statistically significant and clinically robust improvements with nefazodone treatment, which were maintained at follow-up evaluation 2 weeks after the end of nefazodone treatment. There were no adverse events. These results suggest that nefazodone may be a safe and effective adjunct to antipsychotic medications in schizophrenia and that augmentation of 5HT₂ antagonism may prove to be a viable strategy for 'boosting' antipsychotic efficacy and for treating depressive symptoms in schizophrenia.