Prospective study of fluoxetine treatment and suicidal behavior in affectively ill subjects

Objective: There has been speculation in the literature about a link betwee n fluoxetine use and suicidal behavior. The authors of this study hypothesi zed that there is no elevation in risk of suicidal behavior associated with use of fluoxetine. Method: The data come from the National Institute of Me ntal Health Collaborative Depression Study, a prospective, naturalistic fol low-up of persons who presented for treatment of affective disorders. The a nalyses included data on 643 subjects who were followed up after fluoxetine was approved by the Food and Drug Administration in December 1987 for the treatment of depression. Results: Nearly 30% (N=185) of the study group was treated with fluoxetine at some point during the follow-up period. Relativ e to the other subjects, those who were subsequently treated with fluoxetin e had onset of affective illness at a younger age and, after intake into th e study and before 1988, had elevated rates of suicide attempts before fluo xetine treatment. A mixed-effects survival analysis that incorporated treat ment exposure time, multiple treatment trials, and multiple suicide attempt s per subject showed that relative to no treatment, use of fluoxetine and u se of other somatic antidepressants were associated with nonsignificant red uctions in the likelihood of suicide attempts or completions. Severity of p sychopathology was strongly associated with elevated risk, and each suicide attempt after intake into the Collaborative Depression Study was associate d with a marginally significant increase in risk of suicidal behavior. Conc lusions: The results do not support the speculation that fluoxetine increas es the risk of suicide. Rather, there was a nonsignificant reduction in ris k of suicidal behavior among patients treated with fluoxetine, even though those subjects were more severely ill before treatment with fluoxetine.