Print

Email story

Comment

Email editor

Studies counter antidepressant warnings

Two independent studies conclude the drugs seem to reduce the risk of suicidal thinking rather than possibly increasing it as labels caution.

By wire services
Published January 2, 2006

Treatment with antidepressant drugs appears to reduce the risk of suicide in depressed teenagers and adults, according to a study of more than 65,000 patients published Sunday in the American Journal of Psychiatry .

The findings from that and a second independent, federally funded study also published in the journal - the first of their kind - spurred some psychiatrists to call for the Food and Drug Administration to re-evaluate its warnings about the drugs, which have been blamed for a decline in their use.

"The take-home message from these studies is that we have treatment that is effective and that the risk from depression is far greater than the risk of treatment," said Darrel Regier, director of research for the American Psychiatric Association, which publishes the journal and has been critical of the warnings. "These studies are very important."

Some other medical professionals, however, questioned the results, saying they failed, for example, to show that the drugs were more effective or safer than a placebo.

"The big bulk of the response to antidepressants is the placebo response," said Irving Kirsch, a psychologist at the University of Plymouth in England. "I don't think these studies are very informative."

The second study found about 30 percent of patients taking citalopram, a widely used antidepressant sold under the brand name Celexa, recovered fully after 12 weeks of treatment. That figure is comparable to the recovery rate for a placebo, generally estimated at 25 percent to 30 percent. Another 15 percent experienced some improvement.

Critics also said the findings indicate that most patients do not benefit from the drugs.

"These pills can be useful pills, but they don't match up to the hype we've had that they really cure the illness," said psychiatrist David Healy of Cardiff University in Wales.

In 2004 the Food and Drug Administration ordered companies to include a "black box" warning saying that antidepressants could increase suicidal thinking in young people.

That warning was followed by a July 2005 public advisory that said adults beginning on antidepressants should be closely watched because of preliminary studies suggesting that they, too, could be at greater risk of suicidal thinking and behavior.

Since the first warning, prescriptions for antidepressants have been flat for adults, according to NDCHealth, which tracks pharmaceutical information, and they have fallen slightly for adolescents. Antidepressants are among the most widely prescribed drugs in the United States, with almost 200-million prescriptions written a year.

The new studies are the first large-scale efforts to independently evaluate the drugs without using data from drug companies' studies. Both were funded by the National Institute of Mental Health and conducted by independent scientists.

Robert Temple, the FDA's director of medical policy, called the findings "reassuring" but said they do not settle the issue. The agency was continuing to study the drugs' safety in the hopes of clarifying their safety further, he said.

"There's no question that many psychiatrists are worried that the public fuss about suicidality will lead to the failure of some patients to use antidepressants when appropriate. We are very worried about that, too," Temple said.

Dr. Gregory Simon, the psychiatrist who led the study examining suicide risks, said he hoped that it would allay the fears of the parents of teens who are considering taking an antidepressant. "The risk of a serious suicide attempt or a suicide in people taking an antidepressant is quite low, and on average the risk goes down, not up, after people start taking those medicines," Simon said.

Simon is a researcher at Group Health Cooperative, a nonprofit insurer in the Pacific Northwest that covers about 500,000 people. The study examined suicides and hospitalizations for suicide attempts in the medical records of 65,103 members of Group Health who received antidepressants from 1992 to 2003.

The study found that patients were significantly more likely to attempt or commit suicide in the month before they began drug therapy than in the six months after starting it. On one level, that finding is not surprising, because a serious suicide attempt is likely to prompt psychiatric treatment. But if the newer antidepressants posed a significant suicide risk, suicide attempts would probably rise, not fall, after treatment began, Simon said.

In addition, Prozac and the other newer antidepressants, often called SSRIs, for selective serotonin reuptake inhibitors, appeared to be associated with a faster and larger reduction in risk than older classes of antidepressants, which are no longer commonly used.

Dr. Robert Freedman, the editor of the American Journal of Psychiatry , said he believed the study "had real public health implications." The study is not perfect, because it did not compare the experiences of patients who were treated with nondrug therapy or no therapy to those who took an antidepressant, Freedman said.

The FDA generally views the results of randomized clinical trials as more important than those of epidemiological studies like the one conducted by Simon. In a clinical trial, researchers examine the effects of two different treatments on two groups of patients who have carefully been selected so they are identical.

That way, scientists can assume that any difference in the outcomes of the two groups is produced by the two treatments.

But in Simon's study, patients were not given another kind of treatment, so it is difficult to know whether their suicide rates fell because of the antidepressants they were given or for another reason.

Nonetheless, the findings are striking, Freedman said. "This was a huge sample of real patients," he said. "It's the first evidence that the drugs are actually changing suicide rates."

In the second study, researchers tracked 2,876 depressed people taking citalopram under the care of psychiatrists or primary care doctors. Based on a widely used measure of depression, about 28 percent of the patients had recovered fully by the end of the study, with 15 percent showing some improvement.

Another measure showed slightly better results, with 33 percent achieving remission.

The trial did not compare people taking citalopram with those taking other antidepressants, other types of therapy or placebos. But the results were consistent with other clinical trials that show that antidepressants are in general only modestly - if at all - more effective than a placebo in treating depression.

--Information from the New York Times and Washington Post was used in this report.

[Last modified January 2, 2006, 02:30:25]