"Even when we controlled for utilization of healthcare services, diabetics with mental disorders did less well at controlling their diabetes and had more complications than diabetics who had no mental health complaints," said Dr. Carney.

The researchers found that diabetics with mental disorders were more likely to be young, female, and urban residents and to make greater use of healthcare services than the diabetics without mental illness. Mental disorders presented by the diabetics in the study include mood, adjustment, anxiety, cognitive, psychotic, substance abuse and sexual disorders.

"These findings underscore the need for physicians to treat the whole patient - not simply the mental disorders or the physical complaints," said Dr. Carney who is both an internist and a psychiatrist.