The study aimed to determine the prevalence, pattern and correlates of antipsychotic polypharmacy (APP) among outpatients with schizophrenia attending a tertiary psychiatric facility in Nigeria.

A cross-sectional study of 250 patients with schizophrenia attending the outpatient clinic of a regional tertiary psychiatric facility in Nigeria was undertaken. They were administered a sociodemographic questionnaire, the Positive and Negative Syndrome Scale (PANSS), the Global Assessment of Functioning (GAF) scale and the Liverpool University Side Effects Rating Scale (LUNSERS).

Of the 250 subjects interviewed, 176 (70.4%) were on APP. APP was significantly associated with higher prescribed chlorpromazine equivalent doses of antipsychotics (p < 0.001), increased frequency of dosing (p < 0.001), negative symptoms (p < 0.01), poorer functioning (p = 0.04) and greater side-effect burden (p = 0.04).

The APP rate reported from this study is high. Clinicians should be mindful of its impact on dosage and side-effect profiles as APP use is associated with negative symptoms and poor psychosocial functioning.