Adults who enjoy a cup of coffee in the morning may be at a lower risk of suicide.
Men and women who regularly drank several cups were 50 percent less likely to end their own lives, a Harvard School of Health press release reported.
"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," lead researcher Michael, a research fellow in the Department of Nutrition, said.
Researchers assessed the coffee intake of men and women with questionnaires every four years.
Caffeine intake from other sources such as tea, soft drinks, and chocolate, were taken into account, but the majority of participants got most of their caffeine fix from coffee.
Out of a group of 43,599 men and 164,825 women there were only 277 cases of suicide over the course of the study.
The team did not notice a difference in suicide risk between people who drank three cups of coffee, and those who consumed four or more drinks.
A large Finnish study found people who drank eight or nine cups of coffee a day actually had a higher risk of taking their lives.
Very few participants in the new Harvard study drank over six cups a day, so the risk was not assessed
Despite the study's findings, the researchers do not suggest increasing coffee intake to fight depression. Most people drink the amount of coffee that is right for them, and unpleasant side effects could occur if that limit is overstepped.
The recommended daily caffeine consumption is about 200 to 300 milligrams, which is equivalent to about two eight ounce cups of coffee HealthNet reported.
Caffeine overdoses can occur, but the amount one can consume before experiencing symptoms varies from person to person.
Symptoms of an overdose include: dizziness, diarrhea, extreme thirst, irritability, headache, insomnia, and fever.
People suffering from an extreme overdose can experience: breathing problems, vomiting, confusion, chest pains, increased heartbeat, muscle spasms, and even hallucinations and convulsions.
