Efficacy of selegiline add on therapy to risperidone in the treatment of the negative symptoms of schizophrenia: a double-blind randomized placebo-controlled study

Abstract

Objective: It has been reported that selegiline, a Selective Monoamine Oxidase Inhibitor B (MAOI-B), at low doses would be helpful for treating negative symptoms in schizophrenia. Nevertheless, the results are contradictory so far. This study was designed to investigate the effect of selegiline added to risperidone as augmentation therapy in patients with chronic schizophrenia and prominent negative symptoms in an 8 week, double blind and randomized clinical trial.

Methods: Eligible participants in this study were 40 patients with chronic schizophrenia. All patients were inpatients and were in the active phase of the illness, and met DSM-IV-TR criteria for schizophrenia. Patients were allocated in a random fashion, 20 to risperidone 6 mg/day plus selegiline 10 mg/day (5 mg bid) and 20 to risperidone 6 mg/day plus placebo. The principal measure of the outcome was Positive and Negative Syndrome Scale (PANSS).

Results: Although both protocols significantly decreased the score of the positive, negative, and general psychopathological symptoms over the trial period, the combination of risperidone and selegiline showed a significant superiority over risperidone alone in decreasing negative symptoms and PANSS total scores.

Conclusion: The present study indicates selegiline as a potential adjunctive treatment strategy for the negative symptoms of schizophrenia. Nevertheless, results of larger controlled trials are needed before recommendation for a broad clinical application can be made.