Risks of Suicide and Poisoning Among Elderly Patients Prescribed Selective Serotonin Reuptake Inhibitors: A Retrospective Cohort Study

Background: Treatment with selective serotonin reuptake inhibitors (SSRIs) has been associated with increased suicide risk. Risks of suicide death and of poisoning were compared during periods of SSRI treatment versus periods without any antidepressant treatment among elderly patients.

Method: In this retrospective cohort study, records from the Quebec Health Care Fund and Vital Statistics databases were obtained for patients 65 years and older who had filled a prescription for an SSRI between January 1998 and December 2004. Patients were followed from the filling date of the first SSRI prescription during the study period until death, the end of the first period extending for at least 365 days with no antidepressant supply, or December 31, 2004, whichever occurred first.

Results: The cohort included 128,229 patients (mean age = 75.4 years), 70% of whom were women. Numbers of suicide deaths (crude rate/100,000 patient-years) were 37 (23) during SSRI use, 16 (51) during other antidepressant use, 5 (54) during use of both an SSRI and another antidepressant, and 29 (29) during no antidepressant use. The adjusted risk of suicide death (Cox regression model with time-dependent exposure) was not higher during SSRI use versus nonuse (hazard ratio [95% CI]): any SSRI = 0.64 (0.38 to 1.07), paroxetine = 0.71 (0.37 to 1.35), citalopram = 1.16 (0.59 to 2.25), and sertraline = 0.38 (0.16 to 0.93). The adjusted hazard ratio (95% CI) of poisoning was higher during SSRI use versus nonuse (1.16 [1.07 to 1.25]) and varied between SSRI agents from 0.93 (0.74 to 1.16) for fluoxetine to 1.45 (1.23 to 1.71) for fluvoxamine.

Conclusion: Among elderly patients dispensed SSRIs, the risk of suicide death was not higher during periods of SSRI use compared to when antidepressants were not being used.