Which drug is used as monotherapy for schizoaffective disorder?

• A. Clozapine
• B. Paliperidone
• C. Risperidone
• D. Olanzapine

Answer: (B)

Paliperidone is effective as a single-agent therapy for schizoaffective disorder because it treats the core psychotic symptoms while also addressing mood-related features without automatically needing an added mood stabilizer or antidepressant. As a second-generation antipsychotic, it blocks dopamine D2 and serotonin 5-HT2A receptors, reducing hallucinations and delusions and often improving psychiatric symptoms that accompany the mood component of schizoaffective disorder. The extended-release form provides stable, once-daily dosing and its pharmacokinetics are largely renal, with less hepatic interaction, making it convenient and suitable for monotherapy in many patients. While other antipsychotics can be used, paliperidone has specific trial data supporting its use as a single agent in this condition and offers practical advantages like adherence-friendly dosing. Clozapine is typically reserved for treatment-resistant cases, and olanzapine or risperidone may be used but do not have the same level of monotherapy support for this diagnosis in comparison.