A study by the Harvard School of Public Health (HSPH) concluded that drinking several cups of coffee a day could cut the risk of suicide by 50 percent in men and women. According to a report in the Harvard Gazette, researchers found that adults who drink two to four cups of caffeinated coffee per day were half as likely to commit suicide as those who didn't.

Caffeine, in addition to the jolt it provides to the central nervous system, also acts as a mild antidepressant by boosting levels of several key neurotransmitters in the brain, including serotonin, dopamine, and noradrenaline. These chemicals are associated with a sense of well-being, and the study theorized that this would explain the lower incidences of severe depression among coffee drinkers found in previous studies.

“Unlike previous investigations, we were able to assess association of consumption of caffeinated and non-caffeinated beverages, and we identify caffeine as the most likely candidate of any putative protective effect of coffee,” said lead researcher Michel Lucas, research fellow in the Department of Nutrition at HSPH.

According to the Gazette, researchers followed three groups of volunteers for ten years from 1998 to 2008, including 43,599 male health care professionals and 164,825 women health workers. The subjects' intake of coffee, caffeinated beverages and decaffeinated coffee was checked every four years via questionnaire.

The study included all caffeine intake, including sodas, chocolate and tea, but for at least 70 percent of respondents in each tested group, coffee was the main caffeine source. Among the 208,424 volunteers, 277 committed suicide.

Study authors were careful to warn that depressed people should not abruptly increase their coffee drinking as a substitute for seeking help from a mental health professional. Most people, said the study, find their optimal daily dosage of caffeine on their own and stick to it.

Two to four cups a day appears to be the optimal range for the anti-depressive effects of coffee. A study done in Finland actually found that people who drink six or more cups of coffee per day had a slightly elevated suicide risk. Only a very few participants in the HSPH study, however, drank that much coffee each day.

[image of woman enjoying a cup of coffee via Shutterstock.com]