Effect of Add-on Citalopram to Risperidone on Negative Symptoms in Schizophrenia

Negative symptoms in schizophrenia present a challenge to the clinician owing to their poorer response to conventional treatment with antipsychotics. Negative symptoms in schizophrenia may be secondary to psychotic symptoms, depressive symptoms, drug-related side effects or lack of environmental stimulation. Alternately, they may represent core features of the illness, characterized as primary deficit symptoms. Previous studies have suggested that atypical antipsychotics may be beneficial in improving deficit symptoms of schizophrenia. This study aimed at characterizing the nature of improvement of negative symptoms in the early phase (12 weeks) of treatment with the atypical antipsychotic, risperidone. In order to account for factors contributing to improvement in secondary negative symptoms, ratings were carried out of change in positive symptoms, depressive symptoms and drug-related side effects. Further, add-on citalopram or placebo were administered in a double-blind design to study the effect of selective serotonin reuptake inhibitor (SSRI) augmentation of risperidone on negative symptoms. The investigators hypothesized that the improvement in negative symptoms during the initial phase (12 weeks) of treatment with risperidone will be largely accounted for by improvement in secondary negative symptoms, rather than of the primary deficit symptoms.