Antidepressants Increase Suicide Attempts But Not Suicides

KUOPIO, Finland, Dec. 7 -- Antidepressants do not significantly reduce suicide, and those taking the drugs increase attempts, according to a large Finnish study. Yet there was a reduced overall mortality among suicidal patients taking antidepressants.

The 31% to 41% lower relative risk of overall mortality for suicidal patients taking antidepressant medication found in the study was likely attributable to fewer cardiovascular- and cerebrovascular-related deaths, said Jari Tiihonen, M.D, Ph.D., of the University of Kuopio and Niuvanniemi Hospital here, and colleagues.

The study, published in the December issue of Archives of General Psychiatry, included all 15,390 patients hospitalized in Finland for a suicide attempt from 1997 to 2003. The researchers followed patients for an average of 3.4 years afterward using national records.

During follow-up, the adjusted relative risk death of was significantly lower among those taking any antidepressant (0.64, 95% CI 0.56 to 0.73, P

"Because previous suicide attempts are the most important risk factor for predicting suicide," they added, "a large cohort of suicidal patients would be an obvious choice to investigate the association between antidepressant treatment and the risk of suicide."

So the investigators used national insurance, pharmacy and mortality databases to analyze the effects of antidepressant medication on patients who had attempted suicide but had no previous hospitalization for a psychosis diagnosis and were at least 10 years old at their index hospitalization. Among these 7,466 males and 7,924 females, there were 602 suicides, 7,136 suicide attempts leading to hospitalization, and 1,583 deaths during follow-up.

All risk assessments were adjusted for sex, age, number of purchased antidepressant prescriptions during the year before the index date, use of multiple antidepressant medications, number of severe suicide attempts leading to hospitalization during the prior five years, and number of subsequent hospitalizations for suicide attempts.

The researchers found 12% of the overall reduced mortality could be attributed to antidepressant use (population attributable fraction).

In an analysis of patients who had ever used any antidepressant, current use was associated with 39% higher risk of attempted suicide (P

"This opposite type of effect on fatal versus nonfatal suicidal behavior may be explained by an increased risk of intoxication because of easy availability of means (antidepressant medication), resulting in an increase in nonfatal suicidal behavior, and by a decrease in the incidence of violent and more fatal methods of suicide attempts, such as hanging and shooting," they wrote.

The findings may not be generalizable to all suicidal patients since only about half of suicide attempts in Finland are treated in the hospital, so the study population may have been the most severe cases.

Also, these suicidal patients may not be representative of the whole population of patients with depression, but "the effect of SSRIs on cardiovascular- and cerebrovascular-related mortality might apply to all patients receiving antidepressant medication."