The relationship between fluoxetine use and suicidal behavior in 654 subjects with anxiety disorders

In the past few years, there has been controversy over the relationship between suicidal behavior and fluoxetine use. This report examines the relationship between fluoxetine use and suicidal behavior in the Harvard/Brown Anxiety Disorders Research Program (HARP).

HARP is a naturalistic, prospective, longitudinal anxiety disorders study. Probabilities of suicidal behavior for 654 subjects were examined using life table analysis for the study group as a whole and stratified by depression status at intake.

Subjects not using fluoxetine during follow-up had almost twice the probability of making a suicide attempt or gesture during the follow-up than subjects who were using fluoxetine, although this difference was not statistically significant. Subjects having episodes of major depressive disorder (MDD) at intake were more likely than those not having an episode to receive fluoxetine during follow-up (74/166 [45%] vs. 118/488 [24%], chi squared= 24.85, df= 1, p < .0001). Among those subjects having episodes of MDD at intake, there was a statistically significantly lower probability of suicide attempts/gestures for those taking fluoxetine than for those not using fluoxetine during follow-up (log-rank chi squared= 5.10, df= 1, p= .02).

We found no evidence that fluoxetine use is associated with increased risk of suicide attempts or gestures. However, we did find that subjects with more suicide risk factors at intake were more likely to use fluoxetine than those without these risk factors.