Risperidone: review of its therapeutic utility in depression

There is extensive evidence to implicate dysregulation of noradrenergic, serotonergic, and dopaminergic neurotransmission in the pathophysiology of mood disorders. The receptor profile for risperidone, an atypical antipsychotic with demonstrated efficacy in schizophrenia, is consistent with possible antidepressant activity. Specifically, risperidone is a potent antagonist of central 5-HT2A receptors, addressing symptoms such as insomnia, agitation, and weight loss and may indirectly enhance 5-HT1A-mediated neurotransmission. A search of the worldwide medical literature published through December 2000 revealed 24 publications pertinent to the clinical use of risperidone in the treatment of patients with depressive symptomatology. In schizophrenia, in which depression is a common comorbid condition, the results of eight randomized, blinded, and controlled trials consistently demonstrated that treatment with risperidone significantly reduced scores on various measures of depressive symptoms. Moreover, these effects were distinct from improvements in negative and positive symptoms. Antidepressant effects also were observed in two large meta-analyses of trials in patients with schizophrenia or schizoaffective disorder. Observations from uncontrolled studies and case reports of risperidone therapy of other psychiatric disorders were similarly suggestive of antidepressant activity. Collectively, the evidence we present in this review indicates that risperidone's therapeutic benefits in psychiatric medicine extend beyond potent and effective antipsychotic activity and may include effectiveness in treating depression and related affective disorders. Systematic studies are now needed to evaluate the utility of concomitant therapy with an atypical antipsychotic in psychotic, bipolar, and treatment-resistant depressive syndromes.