Nondisordered Cannabis Use Still Impairs Psychiatric, Neural Health

Even recreational, nondisordered cannabis use among adolescents is associated with morphological and potentially neural changes in the brain. These effects have major implications for current and future psychiatric health among this population, according to findings presented at the 2024 American Psychiatric Association (APA) Annual Meeting, held from May 4 to 8, 2024 in New York, New York.

With the widespread decriminalization and legalization of cannabis across the United States, cannabis use has substantially increased – especially among adolescents. The increased ubiquity of cannabis use even led to a new Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) diagnosis of nondisordered cannabis use, which is 4 times more common than cannabis use disorder. However, relatively little is known about the prevalence and trends of nondisordered cannabis use among adolescents since its DSM-5 designation.

To this aim, investigators conducted a systematic review of PubMed for studies that evaluated nondisordered cannabis use among adolescents between 12 and 18 years of age. Additionally, the investigators also leveraged governmental reports that mention nondisordered cannabis use.

The investigators found that even after 30 days of abstinence, nondisordered cannabis use was associated with a variety of psychiatric issues – including a 4-fold increase in the likelihood of cognitive impairment and adult psychosis diagnoses and a 2-fold increase in reports of concentration difficulties. The investigators also observed a dose-response relationship between frequency of cannabis use and rates of attempted suicide.

Adolescents who more frequently used cannabis were 2.5 to 4.5 times more likely to be truant at school and a lower grade-point average was 2.0 to 3.5 times more likely among cannabis users of any frequency.

In brain imaging studies, the investigators found significant changes in the hippocampus, amygdala, prefrontal cortex, and grey matter content among adolescents aged 15 to 17 years who were daily users of cannabis. Given that these brain areas are commonly associated with perceptual reasoning and anxiety, these changes during adolescence could have major implications for long-term mental and cognitive health.

“Cannabis use in teenagers has far-reaching implications for their current and future psychiatric health, most notably for depressive and anxiety disorders,” the investigators concluded, adding, “Studies have shown that cannabis is not innocuous and does change the morphology and, potentially, the neural pathways in the brain.”

This article originally appeared on Psychiatry Advisor