Schizoaffective disorder may require antipsychotic modification when persistent psychotic symptoms coexist with treatment-related adverse effects. We report a 29-year-old woman with schizoaffective disorder who continued to experience prominent auditory hallucinations despite olanzapine 20 mg daily and had developed weight gain and prediabetes. A gradual transition to paliperidone was initiated because of persistent symptoms and metabolic concerns. During cross-titration, she experienced psychiatric destabilization requiring inpatient hospitalization. Following discharge, paliperidone was titrated to 12 mg daily while olanzapine was progressively reduced. Auditory hallucinations persisted but became less intense and less impairing, with concurrent improvement in anxiety, sleep, cognition, and functioning. Olanzapine was subsequently discontinued, and clinical improvement was maintained for approximately two months on paliperidone 12 mg monotherapy. At the most recent follow-up, paliperidone was reduced to 9 mg daily at the patient's request, although response to the lower dose was not yet available. This case highlights the complexity of antipsychotic transitions in schizoaffective disorder and the importance of individualized titration, close monitoring, and balancing symptom control with medication tolerability.

schizoaffective disorder, paliperidone, olanzapine, antipsychotic switching, auditory hallucinations, metabolic adverse effects