Suicide attempts in clinical trials with paroxetine randomised against placebo

Abstract

Background: Inclusion of unpublished data on the effects of antidepressants on children has suggested unfavourable risk-benefit profiles for some of the drugs. Recent meta-analyses of studies on adults have indicated similar effects. We obtained unpublished data for paroxetine that have so far not been included in these analyses.

Methods: The documentation for drug registration contained 16 studies in which paroxetine had been randomised against placebo. We registered the number of suicides, suicide attempts and ideation. We corrected for duration of medication and placebo treatment and used a standard Bayesian statistical approach with varying priors.

Results: There were 7 suicide attempts in patients on the drug and 1 in a patient on placebo. We found that the probability of increased intensity of suicide attempts per year in adults taking paroxetine was 0.90 with a "pessimistic" prior, and somewhat less with two more neutral priors.

Conclusion: Our findings support the results of recent meta-analyses. Patients and doctors should be warned that the increased suicidal activity observed in children and adolescents taking certain antidepressant drugs may also be present in adults.

Figure 1

Prior intensity of suicidal attempt. Distributions of three different prior (see text) logarithmic intensity ratios ln(θd/θp) (logarithmic intensity of a suicide attempt on drug minus logarithmic intensity of a suicide attempt on placebo).

Figure 2

Posterior intensity of suicidal attempt. Distributions of posterior logarithmic intensity ratios ln(θ_d/θ_p) with three different priors.