Do selective serotonin reuptake inhibitors cause suicide?

Editor—Fergusson et al report the association between suicide attempts and use of selective serotonin reuptake inhibitors (SSRIs).¹ A causal link between use of an SSRI and self harm would have drastic clinical implications for health services. The extra monitoring might make using antidepressants wholly impractical in a risk averse service.

The reported incidence of self harm in these studies, with estimates of 0.05-0.001%, is remarkably low. Even during a short trial, such a low incidence among patients with severe depression is not credible. The surely unique finding that rates of fatal and non-fatal self harm are identical among placebo treated patients further emphasises how unsustainable these reported figures must be. It is perhaps unsurprising that in studies designed to evaluate not self harm but efficacy, acts of self harm will be under-reported.

Under-reporting is likely to be more common among placebo treated patients. Although the methods of self harm are not stated, overdose of trial tablets might account for several of these reports. The trial treatments are unequal since SSRIs will cause physical effects (gastrointestinal disturbance) that might prompt attendance at an emergency department. Placebo should provoke no such reaction and thus less need to report such an act of self harm.

Such data have not emerged to a barrage of opprobrium from the pharmaceutical industry. Although popular and endorsed in recent guidelines from the National Institute for Clinical Excellence,² SSRIs no longer have novelty value and are rapidly losing their patents. Data that discredit such old drugs may serve well in marketing the new generation of antidepressants.