Long-term treatment effective in preventing future depressive episodes

Mar 20 2006

People age 70 and older who continued taking the antidepressant that helped them to initially recover from their first episode of depression were 60 percent less likely to experience a new episode of depression over a two-year study period than those who stopped taking the medication, according to a study funded by the National Institute of Mental Health (NIMH).

The study addresses a major question in the treatment of depression - when to discontinue medication.

Published in the March 16, 2006 New England Journal of Medicine, the study showed that long-term treatment (for at least 2 years) after a patient is symptom-free is effective in preventing future depressive episodes.

"This study demonstrates the benefits of keeping older patients on an antidepressant long after they become symptom-free," said NIMH's director Thomas R. Insel, M.D.

The clinical trial tested whether maintenance therapy - long-term treatment given to patients to enable them to maintain a symptom-free or disease-free state - is effective in preventing future episodes of depression in patients 70 years and older. It also tested whether antidepressant medication and psychotherapy were effective, and whether the extent of patients' medical burden had an impact on rates of recurrence.

According to Charles F. Reynolds III, M.D., and colleagues at the University of Pittsburgh, the study speaks directly to the controversy over the benefits and risks of administering long-term antidepressant treatment to elderly patients who have only one lifetime occurrence of major depression. To date, the consensus has been that older patients experiencing their first episode of depression should be treated to full remission and then have a limited period of continuation treatment for 6 to 12 months to ensure the stability of the remission and further improve recovery.

"Most geriatric psychiatrists would not have thought that elderly 70 and older who experienced one episode of depression were candidates for longer term maintenance treatment of up to two years," said Reynolds. "They would agree that elderly with two or more episodes are appropriately prescribed maintenance treatment, but these data allow us to go one step further and suggest that, in fact, even those with single episodes fare considerably better out to two years if they continue use of the medication that got them well."

Patients ages 70 and older with depression who achieved full remission of symptoms after treatment using a combination of paroxetine (a selective serotonin reuptake inhibitor) and interpersonal psychotherapy (IPT) (psychotherapy that focuses on interpersonal relationships) were administered maintenance treatment where researchers tested the effectiveness of different treatment regimens in keeping patients symptom-free for up to 2 years. These patients were randomly assigned to one of four maintenance treatment groups: (1) paroxetine; (2) placebo; (3) paroxetine and monthly interpersonal psychotherapy (IPT); and (4) placebo and IPT.

The study found maintenance treatment was effective in older people with depression. Across all four treatment groups, rates of remission significantly differed. Among patients who received paroxetine in the maintenance phase, 63 percent remained in remission; 42 percent of those who received placebo remained in remission; 65 percent of patients who received paroxetine and IPT remained in remission; and 32 percent of patients who received placebo and IPT remained in remission.

Contrary to the researchers' hypothesis, which predicted that IPT would significantly reduce rates of recurrence, according to the study, IPT did not show preventive efficacy in people 70 years and older.

"But that does not mean that other types of psychotherapy are not effective," said Reynolds. "It could be that this population needs a more structured and focused type of psychotherapy - one that works better with cognitive impairment and greater disability than does IPT - such as problem-solving psychotherapy. Involving caregivers to a greater extent may also help."

The study also showed that older people with multiple chronic physical disorders did not do as well on paroxetine as those with fewer medical problems, although they did show some benefit. The burden associated with more chronic and disabling diseases often drives the depression, making it more difficult to treat, the authors conclude. Despite this, the researchers indicate that maintenance antidepressant medication may be effective in primary care settings where patients have multiple chronic diseases

"What makes this study so practical is that it shows you can combine chronic disease management of depression with the chronic disease management of other illnesses to benefit both the patient's mental illness as well as their physical illness," he said.

The study is part of an overall NIMH effort to conduct practical clinical trials in "real world" settings that address public health issues important to persons affected by major mental illnesses.

http://www.nimh.nih.gov