SANTA MONICA, Calif.–People suffering from depression are less likely to stick to a medication regimen to treat chronic health problems, putting them at increased risk of more serious health issues, according to a study released by the Santa Monica-based RAND Corp.

The study found that depressed patients suffering from chronic illnesses such as diabetes and heart disease were 76 percent less likely to adhere to their medication schedule, when compared to patients who are not depressed.

“These findings provide the best evidence to date that depression is an important risk factor that may influence whether patients adhere to their medications,” RAND natural scientist and senior study author Walid F. Gellad said. “There are important implications for both patient health and for health care costs.

“Doctors and other providers should periodically ask patients with depression about medication adherence.”

The study was conducted by RAND and Claremont Graduate School researchers who combined information from 31 previous reviews involving more than 18,000 people. In addition to heart disease and diabetes, the study evaluated patients suffering from conditions such as high blood pressure, high cholesterol and asthma.

“The consistent link between depression and non-adherence across all these illnesses underscores the seriousness of the role that depression plays in keeping people from properly managing chronic conditions,” according to lead study author Jerry Grenard of Claremont Graduate School.

“That consistency also suggests that lessons learned about how to improve medication adherence among depressed patients with one disease may be applied to other chronic conditions.”