SUNDAY, Jan. 1, 2006 (HealthDay News) -- Contrary to what has been feared, the antidepressants known as serotonin reuptake inhibitors (SSRIs) are initially effective in as many as one-third of depressed patients and don't appear to increase the risk of suicide, two new studies claim.
The reports, both of which were funded by the National Institute of Mental Health, appear in the January issue of the American Journal of Psychiatry.
The suicide findings seem to challenge a 2004 advisory by the U.S. Food and Drug Administration that warned that suicidal behavior may increase after treatment with SSRIs. However, the study did find that suicide attempts were higher among teens than adults, a finding borne out by other research.
The first report is based on early data from the Sequenced Treatment Alternatives to Relieve Depression (STAR*D) trial, the largest study of its kind. This research looked at the benefits of antidepressants in "real world" settings.
"About a third of the patients achieved remission," said lead researcher Dr. Madhukar Trivedi, director of the Mood Disorders Research Program and Clinic at the University of Texas Southwestern Medical Center, in Dallas. "An additional 10 to 15 percent achieved a response."
The object of the study was to provide physicians with guidelines for treating depression, Trivedi said. "The goal is to have patients provided with an adequate dose of medication for an adequate time," he explained. "Treatment would be tailored for each individual patient to get the most benefit from treatment."
For the study, researchers looked at the results of prescribing the SSRI Celexa to 2,876 patients with major depression. These patients also had other physical and psychological problems. The researchers found that about a third of the patients had their depression cured during the first 12 weeks of treatment.
In addition, another 10 percent to 15 percent of the patients showed a response to the medication, or reduction of at least half their symptoms. For patients who did not improve, later phases of the trial will use other medications or combinations of medications to see what might help those who did not benefit from the drug used in the first phase of the trial.
"These antidepressants in routine clinical care produce outcomes comparable with what is seen in research settings," Trivedi said. "These treatments do work in routine clinical care. There also has to be careful monitoring of side effects. In addition, you have to monitor dose and duration of the treatment, based on the patient's progression."
One expert thinks this study will eventually provide guideposts for treating depression that physicians can follow.
"This study, when it is all finally published, will give us a very good idea of how to treat treatment-resistant depression, and what the next step is after the SSRI fails," said Dr. David L. Dunner, director of the University of Washington's Center for Anxiety and Depression.
In the second study, researchers found the risk of suicide attempts and of successful suicides actually dropped in the weeks following the start of SSRI therapy.
"The risk of a serious suicide attempt in people who start taking antidepressant medication is, fortunately, quite low -- less than one in 1,000," said lead author Dr. Greg Simon, a researcher at the Group Health Cooperative, in Seattle. "The risk actually goes down after people start antidepressant medication."
The study also found no increase in suicide risk with the newer antidepressants, such as SSRIs, Simon added. "If anything, our data suggests that with the newer antidepressants there is less risk than with the older antidepressants," he said.
For the study, Simons's team collected data on 65,103 patients who had prescriptions for antidepressants between 1992 and 2003.
The researchers found the number of suicide attempts dropped by 60 percent in adults in the first month after starting treatment. The suicide rate continued to drop in the succeeding five months.
Among all the patients, there were 31 suicides in the six months after starting antidepressant therapy. That rate did not change from one month after starting treatment or in subsequent months.
However, teens had more suicide attempts than adults. Simon's group found that in the first six months of antidepressant treatment, the suicide rate was 314 attempts per 100,000 in teens, vs. 78 attempts per 100,000 in adults. For teens and adults, the rate was highest in the month before treatment and dropped by about 60 percent after treatment began, the researchers found.
In its 2004 warning, the FDA said people taking antidepressants should be closely monitored because of the risk of suicide.
"People should be closely monitored, but not because these drugs are especially risky," Simon said. "The real problem in the treatment of depression is that people start medicine and the medicine has side effects or the medicine doesn't work right away, and they get discouraged and they drop out."
Dunner agreed that close monitoring is essential when prescribing patients antidepressants. "Monitoring depression is very important," he said. "Often people come in for treatment when they are starting to get worse."
Monitoring is needed more for side effects from the drugs than to watch for suicidal behavior, Dunner said. "Suicide is a pretty rare event," he said. "It is more important to monitor for side effects and adherence to the medication."
More information
The American Academy of Family Physicians can tell you more about antidepressants.
