California: suicides down after legalization of medical cannabis

Researchers at the University of California, Irvine, sought to assess the impact of the legalization of medical cannabis on suicide rates. Their results, published in the journal Archives of Suicide Research, show a significant decline in suicide cases in the state of California since 1996—the year Proposition 215, which legalized the medical use of cannabis, was passed.

Is there a causal link?

The researchers compiled annual suicide data by state for the period 1970–2004. They also classified the cases into the categories «suicide by firearm» and «suicide without a firearm.» California was then compared in its pre- and post-legalization periods and against the average suicide mortality rate of 41 states that had not legalized medical cannabis during that period.

Researchers found that the 1996 legalization had resulted in an annual reduction of 398.9 suicides. This is a significant result, especially given that the suicide rate has increased nationwide. 25.4% from 1999 to 2016. Researchers have put forward several theories to explain this reduction:

• Cannabis may alleviate symptoms of depression and thereby reduce suicidal thoughts. In states where cannabis is legal, it is known that more and more patients People seek it out to treat mood disorders, anxiety, and depression.
• Researchers also raise the possibility that cannabis use may lead to a reduction in alcohol consumption which is known to trigger suicidal behavior.

They note, however, that this decline is largely due to the decrease in suicides by firearm (208 out of 398.9). This clarification is important because the legalization of medical cannabis has required restrictions on carrying firearms. Patients who use medical cannabis must, in fact, forfeit their right to carry a firearm. However, the majority of suicides are committed with firearms.

Is this decline due to some segments of the population having more difficulty accessing firearms, or is it attributable to the benefits of cannabis on mental health? It is impossible to answer this question or establish a causal link at this time.

However, a an earlier study (2012) analyzed 17 years of national statistics on suicide mortality (from 1990 to 2007) and found that «the legalization of cannabis is associated with a 5% reduction in the overall suicide rate, 10.9% in the suicide rate among men aged 20–29, and 9.4% in the suicide rate among men aged 30–39.».