Study: Suicide risk cut by drugs
Published: Sunday, January 1, 2006 at 6:01 a.m.
Last Modified: Sunday, January 1, 2006 at 12:00 a.m.
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 todaySunday in The American Journal of Psychiatry.
The study is likely to increase the controversy over whether depressed teenagers should routinely be prescribed newer antidepressants like Paxil and Zoloft.
In October 2004, the Food and Drug Administration ordered drug companies to add strong warnings to the labels of antidepressants after clinical trials suggested that some drugs increased the risk of suicidal thinking and behavior in children and teenagers. The drugs seem to make a small number of patients extremely agitated, a reaction that can lead to violent or suicidal thoughts, psychiatrists say.
Since the warning, prescriptions for antidepressants have been flat for adults, according to NDCHealth, which tracks pharmaceutical information, and they have fallen slightly for adolescents.
Now some psychiatrists say they believe that the pendulum has swung unfairly against the drugs and that depressed people are not receiving treatment that could help them.
But other doctors continue to say that the drugs should be prescribed cautiously, especially because clinical trials have found that the drugs work only modestly better than placebo pills for most patients.
Antidepressants are among the most widely prescribed drugs in the United States, with almost 200 million prescriptions written each year.
A second study, also published Sunday in the psychiatry journal, found that only 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, which is generally estimated at 25 percent to 30 percent.
The National Institute of Mental Health financed both studies, and the doctors who conducted them said that drug companies played no part in analyzing the data. The psychiatry journal is published by the American Psychiatric Association, which represents about 35,000 doctors.
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 teenagers 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 non-drug 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 who were 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.
Patients who were female, white or married were significantly more likely to recover than those who were black, single or male. Response rates were very similar for people being treated by psychiatrists and for those being treated by primary care physicians.
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.
In fact, patients taking the highest doses of citalopram, 50 milligrams a day or more, were actually less likely to improve than those taking lower doses.
The study is part of a longer trial financed by the National Institute of Mental Health that examined ways to treat depression in people who do not respond to initial drug therapy.
Later phases will examine different drugs, multidrug combinations and drugs in combination with therapy, said Dr. Madhukar Trivedi, professor of psychiatry at University of Texas Southwestern Medical Center in Dallas and the study's lead author.
"The good news is, we got a third of patients to remission," he said.
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