Objective: To determine the association between antipsychotic prescriptions and incident dementia in patients with schizophrenia or schizoaffective disorder.

Methods: In this retrospective cohort study, Cox Proportional hazard models estimated the association between antipsychotic prescriptions and incident dementia in participants ≥50 years of age with a schizophrenia/schizoaffective disorder diagnosis over 12 years. Confounding was controlled by E-balance.

Results: Cumulative dementia incidence was significantly greater among those with an antipsychotic prescription compared to those without (7.9% vs 5.5%, P < 0.0001). After controlling for confounding, antipsychotic prescriptions were associated with a 92% increased risk for dementia (HR = 1.92; 95% CI:1.13-3.27). This association was not significant among those aged ≥65 years. Antipsychotic prescription type (eg, first generation, yes or no) did not affect dementia risk but prescription number did.

Conclusions: Antipsychotic prescriptions were associated with almost twice the incidence of dementia compared to patients without in those with schizophrenia/schizoaffective disorder.