Published in the American Journal of Public Health, a group of economics researchers found that medical marijuana laws led to a sharp drop in suicide rates among young men.

The results seem to support the belief that marijuana can be used to cope with stressful life events, says study co-author Daniel Rees, PhD, professor of economics at the University of Colorado Denver.

"In keeping with what advocates of medical marijuana would argue, that is, if you're depressed, if you have to cope with a stressful situation, marijuana actually helps."

Rees notes that some research suggests marijuana works as an anti-depressant, but the evidence isn't conclusive. On the other hand, medical marijuana laws have also been linked to less alcohol consumption – particularly among young men.

Less alcohol consumption following medical marijuana legalization could also explain the drop in suicide rates, he says.

But the study was the first time researchers have looked at medical marijuana laws and suicide rates. Rees believes more research needs to be done to be sure.

"The relationship really does seem to exist. But we don't have a lot to say about mechanism."

Rees, along with co-authors D. Mark Anderson of Montana State University and Joseph Sabia of San Diego State University, compared changes in annual suicide rates between 1990-2007 of states that legalized medical marijuana and states that did not.

Suicide rates seemed to decline overall among the 12 states that passed laws during this period. But the only statistically significant decrease was in men 20-39 years old.

The team's previous research has also shown a strong correlation between medical marijuana laws and reduced traffic fatalities.

No sources of funding were reported

Source: LeafScience