Depression, Diabetic Complications and Disability Among Persons With Comorbid Schizophrenia and Type 2 Diabetes

Background: People with schizophrenia are at increased risk for type 2 diabetes, its complications, depression, and disability. However, little is known about the interrelationships of these 3 factors in adults with schizophrenia and type 2 diabetes. Objective: We sought to assess the number of diabetic complications and depressive symptom severity as predictors of disability and evaluate depressive symptom severity as a mediator of the relationship between diabetic complications and disability in a sample of 62 adults with schizophrenia and type 2 diabetes. Methods: Two- and 3-step sequential regression models were used to evaluate the relationship of depression and number of diabetic complications with disability. Path analysis with bootstrapping was used to evaluate depressive symptom severity as a mediator of the relationship between complications and disability. Results: Diabetic complications significantly predicted disability scores when controlling for age, gender, socioeconomic status, hemoglobin A1C, positive symptom severity, and negative symptom severity. The addition of depression severity scores resulted in a significant increase in explained variance in disability scores. In the final model, only depression severity scores were significantly associated with disability scores. The full model accounted for 56.2% of the variance in disability scores. Path analysis revealed a significant indirect association of diabetic complications to disability through depression severity scores while controlling for all covariates. The association between complications and disability was nonsignificant when depressive symptom severity was included in the model. Conclusions: Depressive symptoms may present an important and tractable target for interventions aimed at reducing disability in people with schizophrenia and type 2 diabetes.