Predictors of quality of life in type 2 diabetes patients with schizophrenia, major mood disorder, and without mental illness

The aim of the current study is to compare the predictors of health-related quality of life in individuals with schizophrenia, major mood disorder, and no mental illness, all with type 2 diabetes.

A total of 100 individuals with schizophrenia, 101 with a major mood disorder, and 99 without mental illness, all with type 2 diabetes, rated their health-related quality of life on the Medical Outcomes Survey, Short Form-12; physical and mental composite scores (PCS and MCS) were calculated. We performed a hierarchical multiple regression on PCS and MCS in each sample starting with a basic set of predictors and then adding diabetes-related variables. We compared the regression weights and incremental variance explained within each group.

The number of co-occurring medical conditions was significantly associated with lower PCS in all three groups and with lower MCS in the no mental illness group. Diabetes-related variables added significant incremental variance to the prediction of PCS in the no mental illness group but not in either psychiatric group.

For persons with diabetes and mental illness, as well as with no mental illness, additional medical conditions exert a strong effect on physical well-being. The impact on quality of life of diabetes-related factors may be lower in persons with diabetes and serious mental illness compared to those with diabetes and no mental illness.