Long-Term Antidepressants to Prevent Depression?
Study Questions Use of Antidepressants to Protect Against Future Episodes of Depression
May 24, 2010 (New Orleans) -- Long-term use of antidepressants may not always be needed to prevent future bouts of depression.
So say researchers whose preliminary study shows that at least two-thirds of depressed patients who will relapse do so in the first six months after stopping antidepressant medication.
"If you don't get depressed within the first six months after coming off the medication, you may not be at any higher risk of being depressed than any other patient," says study researcher Brian Briscoe, MD, a psychiatrist at the University of Louisville, Kentucky.
There's no doubt that antidepressant drugs are effective in the treatment of depression. But controversy exists over whether antidepressants protect against future episodes of depression once a patient has gone into sustained remission, Briscoe tells WebMD.
So he and colleagues reviewed 16 studies conducted to test the hypothesis that antidepressants prevent depression.
The studies all met certain criteria: participants typically had been treated for at least three bouts of major depression; after the most recent episode, they went into remission for an average of four weeks, after which they were assigned to take either an antidepressant or placebo.
The findings were presented at the annual meeting of the American Psychiatric Association.
By 18 months later, relapse rates in the studies ranged from 10% to 30% for patients on antidepressants, compared with 25% to 80% for patients on placebo.
"In each study, it looked like patients on placebo were doing worse in terms of depression relapse than patients on medication," Briscoe says.
"The problem: Almost all the relapses [among people on placebo] occurred in the first six months. After that, there was very little difference," he says.
In the four studies for which the data very available, 67% to 85% of people taking placebo relapsed within six months, Briscoe says. "There was a very rapid rate of relapse starting in the first month."
Michael Norton, MD, of the University of Washington in Seattle, tells WebMD that the findings need to be reviewed and replicated.
If they hold up, "they’ll be very reassuring when you think about how much trouble people have with withdrawal [from antidepressants]."
"If a patient has been off a drug for six months and comes in saying, 'I read I should be on maintenance therapy,' we can tell him, there's no need to reintroduce the drug," Norton says.
Briscoe says that given the rapid rate of relapse after stopping medication, he tapers patients off antidepressant medications slowly.
"For example, I cut their dose by 10% and wait six weeks, so their body chemistry can recuperate, and then shave off 10% more and so on," he says.
The study was not designed to show that strategy works, he says. "But when you think about how long (weeks to months), it takes for these drugs to kick in, why wouldn't it take a while to wean someone off," Briscoe says.
This study was presented at a medical conference. The findings should be considered preliminary because they have not undergone the "peer review" process, in which outside experts scrutinize the data prior to publication in a medical journal.