Cannabis May Produce More Brain Changes in Teens with Bipolar Disorder than in Healthy Teens
At the 2019 meeting of the International Society for Bipolar Disorders, researcher Benjamin Goldstein of Sunnybrook Research Institute in Toronto reported that adolescents with bipolar disorder who smoked marijuana had greater deficits in certain brain areas than did adolescents who did not have bipolar disorder. The areas affected included the dorsal lateral and rostral middle frontal cortex, and middle cortex. Goldstein concluded, “Adolescents with [bipolar disorder] may be particularly sensitive to the neurostructural effects of cannabis.”
Marijuana in general causes adverse changes in brain structure and cognition and vulnerability to paranoia and psychosis. Heavy use in adolescence is associated with an increased incidence of the onset of bipolar disorder and schizophrenia. The Goldstein data suggest several possible causal mechanisms. Those with bipolar disorder may already have brain abnormalities that are exacerbated by marijuana use. Alternatively, marijuana and bipolar disorder together may impact brain structure more than either factor alone would.
