Depression Management Program Linked to Lower Diabetes Mortality

Older depressed patients with diabetes in primary care practices that implement depression care management were less likely to die over a five-year period than were depressed patients with diabetes who received usual care.

That was the finding from a multisite, randomized, controlled trial of a depression care management strategy for primary care patients with and without diabetes. The study appeared in the December 2007 Diabetes Care.

“To our knowledge, this is the first study to report on the relationship between diabetes and mortality in a depression intervention trial,” wrote lead author Hillary Bogner, M.D., of the Department of Family Medicine and Community Health at the University of Pennsylvania, and colleagues. “We believe these findings support the integration of depression evaluation and treatment with diabetes management in primary care.”

The study was part of the Prevention of Suicide in Primary Care Elderly: Collaborative Trial (PROSPECT). Twenty primary care practices in the New York, Philadelphia, and Pittsburgh metropolitan areas participated in the study.

During patient recruitment from May 1999 to August 2001, 584 participants were identified though a two-stage, age-stratified, depression screening of randomly sampled patients and classified as depressed. Of those, 123 (21.2 percent) reported a history of diabetes.

The 20 primary care practices were paired by region (urban versus suburban/sparsely populated), affiliation, size, and population type. Within the 10 pairs, practices were randomly assigned by coin flip to the depression care management intervention or usual care.

The researchers found that depressed patients with diabetes in the intervention practices were significantly less likely to have died during the five-year follow-up than were depressed patients with diabetes who received usual care. Specifically, depressed patients with diabetes in the intervention practices experienced a mortality rate of 68.2/1,000 person-years, whereas depressed patients with diabetes in usual care experienced a mortality rate of 103.4/1,000 person-years.

In contrast, individuals without diabetes experienced no difference in mortality rates between intervention and usual-care practices, suggesting that the intervention attenuates the influence of diabetes on mortality risk among older adults with depression.

The intervention consisted of trained depression care managers offering guideline-concordant recommendations to the primary care physicians and helping patients with treatment adherence. The care managers monitored psychopathology, treatment adherence, response, and side effects and provided follow-up care at predetermined intervals or when clinically necessary.

Patients who refused antidepressants were offered interpersonal psychotherapy by the depression care managers. In the intervention, a first-line antidepressant (citalopram, a selective serotonin reuptake inhibitor) and the interpersonal psychotherapy were provided at no cost.

In usual care, physicians were informed of patients' depression diagnoses. Physicians also received informational materials and treatment guidelines for geriatric depression. No specific recommendations were given to these physicians regarding individual patients except for handling psychiatric emergencies.

Past APA President Michelle Riba, M.D., a professor of psychiatry and associate chair for integrated medicine and psychiatric services at the University of Michigan, called the results “profound” and said they underscore the importance of involvement by psychiatrists in the care of chronic medical conditions.

“We have known for a long time that depression impacts adherence to medications for diabetes and that diabetes impacts on depression,” she told Psychiatric News. “And we have also known that some psychiatric medications impact glycemic control and can modulate diabetes.

“What we haven't known is if you can make a difference by treating the depression using something like a case-management strategy,” Riba said. “This is an important, very well done study in a very high risk group of patients. It makes it clear that treating depression makes a difference in mortality and that it is important for psychiatrists to be involved in the care of patients with chronic medical conditions, such as diabetes.”

Riba said further research on the effect of early intervention with patients at risk for diabetes and depression is needed. “[The current study] looked at a group of elderly patients,” Riba said, “but we know that diabetes starts much earlier, as does depression.”

In the report, Bogner and colleagues say the precise mechanism by which depression may increase mortality in diabetes remains a matter of speculation.“ Both physiologic factors, such as increased inflammation [and] poor glucose regulation, and behavioral processes, such as poor adherence, may link depression with increased mortality in patients with diabetes,” they noted. “The potential mediators between treatment assignment and outcomes for patients with diabetes deserve further study.”

“Diabetes, Depression, and Death: A Randomized Controlled Trial of a Depression Treatment Program for Older Adults Based in Primary Care (PROSPECT)” is posted at<http://care.diabetesjournals.org/cgi/content/full/30/12/3005>.▪