Adolescents and young adults with mood disorders are at increased risk for self-harm and all-cause mortality when they also have cannabis-use disorder, a study shows.

US researchers examined Ohio Medicaid claims data on 204,780 youth aged 10-24 years who had been diagnosed with mood disorders between 2010 and 2017 to see whether risk of self-harm or death from any cause within one year of cannabis-use disorder diagnosis was increased.

Overall, 21,040 (10%) of the young people in the study had cannabis-use disorder.

Over the one-year period after the date of diagnosis, the young people with cannabis-use disorder were at three times the risk for nonfatal self-harm and had nearly 60% higher risk of all-cause mortality compared to those without a cannabis-use disorder diagnosis.