The report, which was funded by the Finnish government, is published in the December issue of the Archives of General Psychiatry.
In recent years, there has been a great deal of concern that SSRI antidepressants might increase the risk for suicide, especially among children and adolescents.
These concerns have led to U.S. Food and Drug Administration-mandated "black box" label warnings on SSRIs that alert physicians and patients to the possibility of suicidal behavior among people taking these drugs. Health officials in the United Kingdom went a step further, banning the use of Prozac in children.
But people who kill themselves are most often older men who use more violent means, such as hanging or shooting themselves, Khan said. On the other hand, "most people who [unsuccessfully] attempt suicide are younger women who are in distress," he said.
Antidepressants can spur an increase in emotions, so it is not surprising that there is a concurrent rise in suicide attempts, Khan explained. "Activation of impulsive behavior occurs, but not death," he said. "Attempted suicide is usually an act of aggression. It is a way of punishing other people and getting a reaction from people."
In the Finnish study, Dr. Jari Tiihonen, from the University of Kuopio and Niuvanniemi Hospital, Kuopio, and colleagues collected data on over 15,000 people hospitalized in Finland for suicide attempts between 1997 and 2003. The researchers followed these people for an average of 3.4 years to see if they tried suicide again, completed suicide or died from other causes.
Tiihonen's team found that among 7,466 men and 7,924 women in the study, there were 602 suicides, 7,136 attempted suicides and 1,583 deaths during the follow-up period.
The researchers report that the risk of completed suicide was 9 percent lower among people taking any antidepressants compared with people not taking the drugs.
The association varied by antidepressant type, Tiihonen's group found. For example, people taking fluoxetine (Prozac) had a 48 percent lower risk of suicide compared with those not taking medication, but people taking venlafaxine hydrochloride (Effexor) had a 61 percent increased risk.
Effexor is in another class of antidepressants called serotonin-norepinephrine reuptake inhibitors (SNRIs). These drugs work on both serotonin and another neurotransmitter, norepinephrine.
When it came to suicide attempts, people taking an antidepressant had a 36 percent increased risk of an attempt leading to hospitalization compared with people not taking antidepressants, the researchers report. There was a slightly greater increase in risk for suicide attempts among children 10 to 19 taking antidepressants compared with children not taking antidepressants, the researchers noted.
Among people who had ever taken an antidepressant, those currently using them had a 39 percent increase in risk of attempted suicide, but a 32 percent decrease in risk of completed suicide and a 49 percent reduced risk of death from any cause, the researchers found.
Another expert said the findings make sense.
Robert D. Gibbons, the director of the Center for Health Statistics and a professor of biostatistics and psychiatry at the University of Illinois, Chicago, said that people who are using antidepressants are, of course, depressed -- and, therefore, still at higher risk of attempting suicide, even though they have started taking the medications.
On the other hand, many people who succeed in killing themselves may have been depressed but did not seek treatment for their depression, Gibbons said. "This is the big concern about 'black box' warnings," he said. "They increase the rate of untreated depression and can ultimately increase the rate of completed suicide."
More information
There's more on suicide prevention at the U.S. National Institute of Mental Health.
