It was reported that
ritanserin, a 5HT2A/2C antagonist, improves negative symptoms when added to
neuroleptics in inpatients with predominantly negative symptoms. Nevertheless, the results of published studies are contradictory so far. This study was designed to investigate the effect of
ritanserin added to
risperidone as augmentation
therapy in patients with chronic
schizophrenia and prominent negative symptoms in a double blind and randomized clinical trial. 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
ritanserin 12 mg/day (6 mg bid) and 20 to
risperidone 6 mg/day plus placebo. The principal measure of the outcome was Positive and Negative Syndrome Scale (PANSS). Although both protocols significantly decreased the score of the positive, negative and general psychopathological symptoms over the trial period, the combination of
risperidone and
ritanserin showed a significant superiority over
risperidone alone in decreasing negative symptoms and PANSS total scores. The present study indicates
ritanserin 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.