For many adults, there's nothing like a good, hot cup of coffee to get you going in the morning. Caffeine, the ingredient in coffee that helps to wake you, is the most widely used stimulant in the United States. Americans consume about 80 percent of their caffeine in coffee.
If you've ever wondered if coffee affects your mood, you're not alone. Many researchers have evaluated caffeine on mental health.
A recent study suggests that depression risk in older women, average age 63, decreases with an increase in caffeine consumption. This was an observational study and relied on participants' own reports of caffeine consumption, which may bias the results. The study does not prove caffeine reduces the risk of depression; it only suggests the possibility of a protective effect. The authors conclude that this study adds to the body of evidence that there isn't much harm in coffee consumption.
Although caffeine may be associated with reduced risk of depression, when consumed in excess, or by people who have mental health disorders, it can be harmful. For example, caffeine may induce anxiety, and for patients with panic disorder, it may even induce panic attacks.
Adults are not the only ones who consume caffeine. Seventy-five to 90 percent of children drink at least one caffeinated beverage daily. Just as it does in adults, caffeine can improve performance on attention-related tasks and reduce sluggishness. However, caffeine can also exacerbate negative mood characteristics, such as anxiety and irritability. When caffeine-drinking children abstain, they experience negative mood and decreased reaction time. Self-reported anxiety and depression symptoms are also elevated in caffeine-dependent adolescents. Caffeine may lead to sleep disturbances, which is an important feature of depression in youth.
Furthermore, at least one study found that youth with depression tend to consume more caffeine than their healthy peers, leading researchers to suspect they may use caffeine to ease their depression symptoms.
The increasing use of high-energy drinks is also troublesome. These drinks contain doses of caffeine that exceed limits set by the FDA (72 mg/12 ounces), and drinkers can actually become intoxicated with overconsumption. High-energy drinks can be addictive and cause withdrawal symptoms. Individuals who overindulge in beverages with large quantities of caffeine often present with generalized anxiety disorder or depression.
The bottom line is that there is no clear link between caffeine and depression, although the two may be indirectly linked in individuals who are especially sensitive to caffeine or who consume it in excess.
Sources:
Neighmond, Patti. "Caffeinated Women May Be Fighting Depression With Every Cup." NPR.org. Web. 27 September 2011. (http://www.npr.org/blogs/thesalt/2011/09/27/140837983/caffeinated-women-may-be-fighting-depression-with-every-cup?sc=fb&cc=fp)
ScienceDaily. "Coffee Drinkers Have Slightly Lower Death Rates, Study Finds." Web. 17 June 2008.
http://www.sciencedaily.com/releases/2008/06/080616170839.htm
Whalen, Diana J., BS, Silk, Jennifer S., PhD, Semel, Mara, MS, Forbes, Erika, PhD, Ryan, Neal D., MD, Axelson, David A., MD, Birmaher, Boris, MD, and Dahl, Ronald E., MD. "Caffeine Consumption, Sleep, and Affect in the Natural Environments of Depressed Youth and Healthy Controls." Journal of Pediatric Psychology 33(4) (2008): 358-367. Medscape Medical News. Web. 18 June 2008.
http://www.medscape.com/viewarticle/575003
Busko, Marlene. "Caffeine Challenge Induced Panic Attacks in Patients with Panic Disorder." Medscape Medical News. Web. 22 June 2007. http://www.medscape.com/viewarticle/558744
Pohler, Holly. "Caffeine Intoxication and Addiction." Journal for Nurse Practitioners 6(1) (2010): 49-52. Medscape Medical News. Web. 20 January 2010. http://www.medscape.com/viewarticle/714855
Hall-Flavin, Daniel K., M.D. "Does caffeine make depression worse?" Mayo Clinic. Web. 12 October 2011.
http://www.mayoclinic.com/health/caffeine-and-depression/AN01700
