:

“We estimated the association between legalizing medical marijuana and suicides.

Legalization was 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.

The negative relationship between legalization and suicides among young men is consistent with the hypothesis that marijuana can be used to cope with stressful life events.” https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4232164/

http://www.ncbi.nlm.nih.gov/pubmed/24432945

http://ajph.aphapublications.org/doi/10.2105/AJPH.2013.301612

“Legalizing Medical Marijuana May Lead To Fewer Suicides”  https://www.huffingtonpost.com/2014/02/04/marijuana-legalization-suicide_n_4726390.html

“Medical Marijuana Cuts Suicide Rates By 10% In Years Following Legalization”  http://www.medicaldaily.com/medical-marijuana-cuts-suicide-rates-10-years-following-legalization-268472