A new study by the American Journal of Public Health found that legalization of medical marijuana is associated with a 10.8% and 9.4% reduction in the suicide rate of men aged 20 through 29 years and 30 through 39 years, respectively
Suicides among men aged 20 through 39 years fell after medical marijuana legalization compared with those in states that did not legalize.
Note: The comparison is with states that did not legalize -- I'd like to see the comparison in the same state for the five years preceding legalization.