Cannabis Use among Youths Increases the risk of Self-Harm and Homicide

The regular use of cannabis during adolescence is of profound concern as use in this age group is associated with an increased likelihood of deleterious consequences, such as diminished scholastic achievement, lower degree attainment and school abandonment, liability to addiction, earlier onset of psychosis and neuropsychological decline. Cannabis use and cannabis use disorder (CUD) are common among youths and young adults with mood disorders but the association of CUD with self-harm, suicide, and overall mortality risk is poorly understood in this already vulnerable population. Therefore, researchers of America, conducted a study, to examine associations of CUD with self-harm, suicide, and overall mortality risk in youths with mood disorders.

It was a population-based retrospective cohort study was performed using Ohio Medicaid claims data linked with death certificate data. Researchers analyzed a total of 204,780 youths aged between 10 and 24 years with a diagnosis of a mood disorder between July 1, 2010, and Dec 31, 2017, in their analysis. The major outcome assessed was nonfatal self-harm, all-cause mortality, and deaths by suicide, unintentional overdose, motor vehicle crashes, and homicide. Researchers used marginal structural models with inverse probability weights to examine the associations between CUD and outcomes.

Key findings of the study were:

• Researchers documented the Cannabis use disorder in 10.3% of youths with mood disorders and were significantly associated with older age, male sex, black race, bipolar or other mood disorders, prior history of self-harm, previous mental health outpatient visits, psychiatric hospitalizations and mental health emergency department visits.

• They noted that youth diagnosed with bipolar disorders and other mood disorders were at an increased risk for CUD compared with those with a depressive disorder (bipolar: adjusted RR, 1.24; other mood disorders: aRR, 1.2)

• They also noted that the cannabis use disorder was significantly associated with nonfatal self-harm (adjusted hazard ratio [AHR], 3.28) and all-cause mortality (AHR, 1.59), including death by unintentional overdose (AHR, 2.40) and homicide (AHR, 3.23).

• They observed that the CUD was associated with suicide in the unadjusted model; however, they found no significant association in adjusted models.

The authors concluded, "Cannabis use disorder is a common comorbidity and risk marker for self-harm, all-cause mortality, and death by unintentional overdose and homicide among youths with mood disorders. These findings should be considered as states contemplate legalizing medical and recreational marijuana, both of which are associated with increased CUD."

For further information:

https://jamanetwork.com/journals/jamapediatrics/article-abstract/2775255