A new wide-scale longitudinal study has found what had been suspected for some time: The treatment of recognized depressive disorders leads to a reduction of patients’ use of nonroutine medical services over the long term.

The study, published in the March Annals of Behavioral Medicine, followed more than 420 patients for 10 years, each receiving treatment for unipolar depression upon entering the study. The study characterized nonroutine medical services as services other than regularly scheduled physicals, preventive care, and disease monitoring. The patient group was compared with a similar group of adults in the same communities who were not being treated for depressive disorders.

Each patient was queried regarding his or her depressive symptoms and use of nonroutine medical services in the year prior to entering the study. Follow-up occurred one, four, and 10 years after entering the study.

The depressed patients showed a far higher rate of utilization of nonroutine medical services compared with the control group upon entering the study. Over the study period, after controlling for the effects of any chronic illness, the patient group showed significant decreases in depressive symptoms, but not to the level of the control group. This indicated a possible chronic component to the depressive disorders. The patients’ rate of utilization remained high at one year, declined significantly at the four-year follow-up, then remained unchanged between the four- and 10-year follow-up interviews.

According to Rachel Kimerling, Ph.D., one of the authors of the study, the depressive symptoms and the rate of utilization showed a synergistic relationship.

"You cannot separate treatment for depressive disorders from other areas of medical care. You have to look at it both ways," said Kimerling, now an assistant adjunct professor in the department of psychiatry at the University of California, San Francisco, School of Medicine.

"People with chronic illness need to be evaluated for depressive disorders as well as patients with depressive disorders being looked at for the development of physical illnesses."

The study suggests that by recognizing and studying the interconnection between physical and emotional well-being, a relationship may develop between treating emotional well-being and reducing patient utilization and therefore reducing health care costs. 

The research was conducted in the Veterans Affairs Palo Alto Health Care System and Stanford University School of Medicine.