Background:

‍Caffeine is the world’s most widely used central nervous system stimulant, with approximately 80% consumed in the form of coffee. However, studies that analyze prospectively the relationship between coffee or caffeine consumption and depression risk are scarce.

Methods:

‍A total of 50,739 US women (mean age,63 years) free of depressive symptoms at baseline (in 1996) were prospectively followed up through June 1, 2006. Consumption of caffeine was measured from validated questionnaires completed from May 1, 1980, through April 1, 2004, and computed as cumulative mean consumption with a 2-year latency period applied. Clinical depression was defined as self-reported physiciandiagnosed depression and antidepressant use. Relative risks of clinical depression were estimated using Cox proportional hazards regression models.

Results:

‍During 10 years of follow-up (1996-2006), 2607 incident cases of depression were identified. Compared with women consuming 1 or less cup of caffeinated coffee per week, the multivariate relative risk of depression was 0.85 (95% confidence interval, 0.75-0.95) for those consuming 2 to 3 cups per day and 0.80 (0.64-0.99; P for trend <.001) for those consuming 4 cups per day or more. Multivariate relative risk of depression was 0.80 (95% confidenceinterval, 0.68-0.95; P for trend=.02) for women in the highest (more than 550 mg/d) vs lowest

Conclusions:

In this large longitudinal study, we foundthat depression risk decreases with increasing caffeinatedcoffee consumption. Further investigations areneeded to confirm this finding and to determine whetherusual caffeinated coffee consumption can contribute todepression prevention.

Arch Intern Med. 2011;171(17):1571-1578