"Adolescent cannabis use was linked to higher risks of later psychotic, bipolar, depressive, and anxiety disorders.
A large new study published in JAMA Health Forum on Feb. 20, 2026, reports that teens who use cannabis may have a substantially greater chance of developing serious psychiatric conditions by young adulthood.
The longitudinal study followed 463,396 adolescents ages 13 to 17 through age 26 and found that cannabis use in the past year during adolescence was associated with significantly higher risks of newly diagnosed psychotic disorders, which doubled; bipolar disorders, which doubled; depressive disorders; and anxiety disorders.
On average, cannabis use was recorded 1.7 to 2.3 years before a psychiatric diagnosis appeared. Because the study followed adolescents over time, its design adds stronger evidence that cannabis exposure during the teen years may be a risk factor for later mental illness.
“As cannabis becomes more potent and aggressively marketed, this study indicates that adolescent cannabis use is associated with double the risk of incident psychotic and bipolar disorders, two of the most serious mental health conditions,” said Lynn Silver, M.D.
Cannabis is the most commonly used illicit drug among adolescents in the United States. The Monitoring the Future study shows that use increases as students get older, rising from about 8% in 8th grade to 26% in 12th grade.
THC levels in California cannabis flower now exceed 20%, far above levels seen in earlier decades, while cannabis concentrates can contain more than 95% THC.
“Even after accounting for prior mental health conditions and other substance use, adolescents who reported cannabis use had a substantially higher risk of developing psychiatric disorders—particularly psychotic and bipolar disorders,” said Kelly Young-Wolff, Ph.D., lead author of the study."
A large new study published in JAMA Health Forum on Feb. 20, 2026, reports that teens who use cannabis may have a substantially greater chance of developing serious psychiatric conditions by young adulthood.
On average, cannabis use was recorded 1.7 to 2.3 years before a psychiatric diagnosis appeared. Because the study followed adolescents over time, its design adds stronger evidence that cannabis exposure during the teen years may be a risk factor for later mental illness.
“As cannabis becomes more potent and aggressively marketed, this study indicates that adolescent cannabis use is associated with double the risk of incident psychotic and bipolar disorders, two of the most serious mental health conditions,” said Lynn Silver, M.D.
Cannabis is the most commonly used illicit drug among adolescents in the United States. The Monitoring the Future study shows that use increases as students get older, rising from about 8% in 8th grade to 26% in 12th grade.
THC levels in California cannabis flower now exceed 20%, far above levels seen in earlier decades, while cannabis concentrates can contain more than 95% THC.
“Even after accounting for prior mental health conditions and other substance use, adolescents who reported cannabis use had a substantially higher risk of developing psychiatric disorders—particularly psychotic and bipolar disorders,” said Kelly Young-Wolff, Ph.D., lead author of the study."
SciTechDaily
