The relationship between antidepressant medication use and rate of suicide

Background: Approximately 30000 people die annually by suicide in the United States. Although 60% of suicides occur during a mood disorder, mostly untreated, little is known about the relationship between antidepressant medication use and the rate of suicide in the United States. Objective: To examine the association between antidepressant medication prescription and suicide rate by analyzing associations at the county level across the United States. Design: Analysis of National Vital Statistics from the Centers for Disease Control and Prevention. Setting: All US counties. Participants: All US individuals who committed suicide between 1996 and 1998. Main Outcome Measures: National county-level suicide rate data are broken down by age, sex, income, and race for the period of 1996 to 1998. National county-level antidepressant prescription data are expressed as number of pills prescribed. The primary, outcome measure is the suicide rate in each county,expressed as the number of suicides for a given population size. Results: The overall relationship between antidepressant medication prescription and suicide rate was not significant. Within individual classes of antidepressants, prescriptions for selective serotonin reuptake inhibitors (SSRIs) and other new-generation non-SSRI antidepressants (eo. nefazodone hydrochloride, mirtazapine, bupropion hydrochloride, and venlafaxine hydrochloride) are associated with lower suicide rates (both within and between counties). A positive association between tricyclic antidepressant (TCA) prescription and suicide rate was observed. Results are adjusted for age, sex. race. income, and county-to-county variability in suicide rates. Higher suicide rates in rural areas are associated with fewer antidepressant prescriptions, lower income. and relatively more prescriptions for TCAs. Conclusions: The aggregate nature of these observational data preclude a direct causal interpretation of the results. A high number of TCA prescriptions may be a marker for those counties with more limited access to quality menial health care and inadequate treatment and detection of depression: which in turn lead to increased suicide rates. By contrast. increases in prescriptions for SSRIs and other new-generation non-SSRIs are associated with lower suicide rates both between and within counties over time and may reflect antidepressant efficacy, compliance, a better quality of menial health care, and low toxicity in the event of a suicide attempt by overdose.