(CBS News) An apple a day is said to keep the doctor away. But, in order to take care of your mental health, you may want to add two cups of coffee to your routine.
A new study published in the July issue of the World Journal of Biological Psychiatry showed that people who drank more than four cups of coffee daily had over a 50 percent lower chance of taking their own lives than those who drank less than one cup.
Researchers looked a data from 208,424 people. About 70 to 80 percent of them said they were coffee drinkers. The subjects were tracked from 1988 to 2008. During the period, there were 277 deaths by suicide.
Those who drank two to three cups daily had a 45 percent lower risk of suicide compared to those who drank less than one cup. For those who drank more than four cups a day, their rates dropped to 53 percent.
The researchers believe that the caffeine in coffee can increase neurotransmitters like serotonin, dopamine and noradrenalin. This can boost a person's mood and act as a mild antidepressant, given the drugs target these neurotransmitters.
"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," study author Michel Lucas, a research fellow in the department of nutrition at Harvard School of Public Health, said in a statement.
This findings may not be the only good thing that coffee can do for you. A March study in Stroke showed that those who drank at least one cup of coffee or green tea a day had a 20 percent lower stroke risk than those who rarely drank the beverage. Heavy coffee drinking -- four or more cups a day - was associated with a 50 percent lower chance of dying from oral and pharyngeal cancers compared to those who didn't consume the drink.
However, coffee-fiends may be putting their mental health at risk if they drink too much java. The new edition of the DSM-5 lists caffeine intoxication and withdrawal as a psychiatric disorders. Intoxication is defined as experiencing five or more symptoms, including restlessness, nervousness, excitement, red face, gastrointestinal upset, muscle twitching, rambling speech, sleeplessness, rapid and irregular heartbeat. Withdrawal can bring about headache, fatigue, difficulty concentrating, a depressed mood and other issues.
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