Blog | Monday, July 29, 2013

QD: News Every Day--Coffee drinkers may have lower suicide rates

Three large cohort studies support an association between coffee and lower risk of suicide (at least in health professionals).

To evaluate the association between coffee and caffeine consumption and suicide risk, researchers accessed data of nearly 44,000 men in the Health Professionals Follow-up Study (HPFS, 1988 to 2008), nearly 74,000 women in the Nurses' Health Study (NHS, 1992 to 2008), and 91,000 women in the NHS II (1993 to 2007).

Coffee and decaffeinated coffee use was assessed every four years by questionnaires. Deaths from suicide were determined by physician review of death certificates. Results appeared online at the The World Journal of Biological Psychiatry.

There were 277 deaths from suicide. Compared to those consuming one cup a week of caffeinated coffee or less, the pooled multivariate relative risk (RR) of suicide for those drinking two to three cups a day was 0.55 (95% confidence interval [CI], 0.38 to 0.78) and for those drinking four or more cups a day was 0.47 (95% CI, 0.27 to 0.81) (P for trend less than 0.001).

The pooled multivariate relative risk for suicide was 0.75 (95% CI, 0.63 to 0.90) for each two cups per day of caffeinated coffee and 0.77 (95% CI, 0.63 to 0.93) for each increment of 300 mg/day of caffeine.