Placebo-controlled clinical trials have led to concern over possible increased risk of suicide-related events in some populations exposed to antidepressants.

To evaluate the risk of suicide attempts by antidepressant drug class and the presence or absence of depression.

A retrospective propensity-matched new-user cohort study was used to compare participants with incident depression classified by antidepressant treatment with each other and with the general population.

Among the treated group, the suicide attempt rate peaked in the month prior to diagnosis then decreased steadily over the next 6 months. Among the pharmacologically untreated group, the highest rate was seen in the second month after diagnosis. Cohorts with depression had significantly higher suicide attempt risk than the general population, but the treated group did not differ significantly from the untreated group.

Patients on antidepressants did not have significantly higher risk compared with untreated patients. No significant differences were observed for patients treated with individual serotonin–noradrenaline reuptake inhibitors (SNRIs) or selective serotonin reuptake inhibitors (SSRIs) or by class (SSRI v. SNRI cohorts).