Prevalence of Diabetes Mellitus Among Outpatients With Severe Mental Disorders Receiving Atypical Antipsychotic Drugs

Background: Recent studies have suggested that patients receiving atypical antipsychotic drugs are at increased risk for developing diabetes mellitus. The purpose of this study is to examine the prevalence of diabetes in a group of adults with schizophrenia and other severe mental disorders receiving atypical antipsychotic drugs within a community mental health center setting.

Method: A retrospective chart review was conducted on 436 outpatients receiving either atypical antipsychotic or decanoate antipsychotic drugs at a community mental health center. Diagnosis of diabetes was established through the presence of documentation in the medical record. Patients with a history of diabetes prior to age 18 years were excluded. Data were gathered from April 2001 through September 2002.

Results: The mean (SD) age of patients was 42.5 (10.8) years, and 57.3% were men. Patients were 61.5% white, 31.8% black, 5.3% Hispanic, and 2.3% other. Seventeen percent of patients had a positive family history of diabetes. Point prevalence of diabetes was 14.2% for the entire group. Chi-square analysis for the group revealed significant effects of age (chi² = 16.514, p < .001), family history of diabetes (chi² = 27.128, p < .001), and gender (chi² = 14.114, p < .001). A trend was noted toward a higher prevalence of diabetes among patients receiving atypical drugs (15.2%) compared with those receiving decanoate drugs (6.3%) (chi² = 2.984, p = .078).

Conclusion: Prevalence of diabetes mellitus among outpatients with severe mental disorders receiving atypical antipsychotic drugs is substantially higher than that reported in the general population. Results of this study are limited by the retrospective methodology, which may underestimate actual prevalence by failing to detect undiagnosed cases.