In patients with type 2 diabetes, the adult on-set variety, depressive symptoms - even if they do not meet criteria for major depressive disorder - is associated with poor adherence to self-care, according to results of a study published in Diabetes Care.

Dr. Jeffrey S. Gonzalez, of Massachusetts General Hospital, Boston, and colleagues compared the effects of depression on 879 diabetic patients from two primary care clinics. The participants were surveyed using the Harvard Department of Psychiatry/National Depression Screening Day Scale (HANDS), the Summary of Diabetes Self-Care Activities, and self-reported medication adherence.

Overall, 19.3 percent of the patients met HANDS criteria for probable major depression (HANDS score at least 9) and 66.5 percent reported at least some depressive symptoms without meeting the criteria for probable major depression.

Only 14.2 percent of the subjects reported no depressive symptoms.

Of those with probable major depression, 59.4 percent had depression listed in their medical records, and 48.8 percent had been prescribed an antidepressant agent.

A significant association was observed between major depression and poorer adherence to diet, exercise, and glucose self-monitoring regimens after controlling for other health risk factors. Patients with major depression had a had 2.3-fold increased odds of missing medication doses in the previous week compared with the other subjects.

Among the 709 subjects who did not meet the criteria for major depression, “increasing HANDS scores were incrementally associated with poorer adherence to self-care behaviors,” the investigators found.

“The presence of symptoms of depression in type 2 diabetes may hinder a patient’s ability to adhere to their self-care routine,“Gonzalez said in an interview with Reuters Health. “Depressive symptoms such as diminished interest, fatigue, concentration difficulties, and feelings of hopelessness could each interfere with the hard work that’s involved in diabetes self-management.”

“These patients might benefit from extra support or from a referral to psychological services, especially when their symptoms are impacting functioning or causing distress,” Gonzalez added. “Since we know that depression in diabetes is associated with higher risks of complications, poorer diabetes control, and even increased mortality, it’s really crucial to evaluate patients and offer appropriate treatment when necessary.”

More generally, Gonzalez concluded, “Our findings suggest that decreased ability to adhere to one’s medical regimen may be an important explanatory pathway through which depression affects health outcomes. Treating depression in the context of chronic illness may be an increasingly important role for mental health providers as rates of chronic illness continue to increase and evidence mounts for the harmful effects of depression in patients with chronic illness.”

SOURCE: Diabetes Care, September 2007.