Adolescents and young adults with mood disorders and cannabis use disorder (CUD) are at significantly increased risk for self-harm, all-cause mortality, homicide, and death by unintentional overdose, new research suggests.
Dr. Cynthia Fontanella
Investigators found the risk for self-harm was three times higher, all-cause mortality was 59% higher, unintentional overdose was 2.5 times higher, and homicide was more than three times higher in those with versus without CUD.
“The take-home message of these findings is that we need to be aware of the perception that cannabis use is harmless, when it’s actually not,” lead author Cynthia Fontanella, PhD, associate professor of psychiatry, Ohio State University Wexner Medical Center, Columbus, said in an interview.
“We need to educate parents and clinicians that there are risks associated with cannabis, including increased risk for self-harm and death, and we need to effectively treat both cannabis use disorder and mood disorders,” she said.
The study was published online Jan. 19, 2021, in JAMA Pediatrics.
Little research in youth
“There has been very little research conducted on CUD in the adolescent population, and most studies have been conducted with adults,” Dr. Fontanella said.
Research on adults has shown that, even in people without mood disorders, cannabis use is associated with the early onset of mood disorders, psychosis, and anxiety disorders and has also been linked with suicidal behavior and increased risk for motor vehicle accidents, Dr. Fontanella said.
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“We were motivated to conduct this study because we treat kids with depression and bipolar disorder and we noticed a high prevalence of CUD in this population, so we were curious about what its negative effects might be,” Dr. Fontanella recounted.
The researchers analyzed 7-year data drawn from Ohio Medicaid claims and linked to data from death certificates in 204,780 youths between the ages of 10 and 24 years (mean age was 17.2 years at the time of mood disorder diagnosis). Most were female, non-Hispanic White, enrolled in Medicaid because of poverty, and living in a metropolitan area (65.0%, 66.9%, 87.6%, and 77.1%, respectively).
Participants were followed up to 1 year from diagnosis until the end of enrollment, a self-harm event, or death.
Researchers included demographic, clinical, and treatment factors as covariates.
Close to three-quarters (72.7%) of the cohort had a depressive disorder, followed by unspecified/persistent mood disorder and bipolar disorder (14.9% and 12.4%, respectively). Comorbidities included ADHD (12.4%), anxiety disorder (12.3%), and other mental disorders (13.1%).
One -tenth of the cohort (10.3%) were diagnosed with CUD.
CUD treatment referrals
“Although CUD was associated with suicide in the unadjusted model, it was not significantly associated in adjusted models,” the authors reported.
Dr. Fontanella noted that the risk for these adverse outcomes is greater among those who engage in heavy, frequent use or who use cannabis that has higher-potency tetrahydrocannabinol (THC) content.
Reasons why CUD might be associated with these adverse outcomes are that it can increase impulsivity, poor judgment, and clouded thinking, which may in turn increase the risk for self-harm behaviors, she said.
She recommended that clinicians refer youth with CUD for “effective treatments,” including family-based models and individual approaches, such as cognitive behavioral therapy and motivational enhancement therapy.