A retrospective cohort study of diabetes mellitus and antipsychotic treatment in the United States.

Treatment-emergent diabetes mellitus (DM) has been described for conventional and atypical antipsychotics. In our study, antipsychotic prescription claims from AdvancePCS's database were used to identify patients starting antipsychotic monotherapy. The relative risk of developing DM was determined using prescription claims for antidiabetic agents in the following cohorts: AdvancePCS general patient population, combined conventional antipsychotics, and combined atypical antipsychotics. Cox proportional hazards regression was used to adjust for differences in age, gender, and duration of antipsychotic exposure between cohorts in the estimation of risk of developing diabetes. Hazard ratios for developing DM in the combined conventional, combined atypical, and individual conventional and atypical antipsychotic treatment cohorts were greater than the AdvancePCS general patient population cohort. An increased risk of developing diabetes compared with the AdvancePCS general patient population was observed during treatment with conventional or atypical antipsychotics.