The psychoactive constituent of marijuana, delta-9-tetrahydrocannabinol (THC), causes significant and persistent behavioral changes, according to researchers at Western University’s Schulich School of Medicine & Dentistry. The study, published in the journal Cerebral Cortex, shows that the long-term impacts of THC in adolescence are similar to that of the symptoms of schizophrenia.

The results were based on a study conducted to adolescent and adult rodents. Adolescent rodents exhibited neuronal and molecular changes similar to neuropsychiatric conditions after receiving doses of THC. However, the adults did not manifest similar changes.

The study, led by Steven Laviolette, a professor of Anatomy, Cell Biology, as well as Psychiatry, involved identifying and assessing behaviors that are seen in schizophrenia and other mental disorders which are cognition, exploratory behaviors, anxiety levels, neuronal or molecular changes, social skills and cognitive disorganization and the inability to focus on the necessary information.

The research team also included lead author Justine Renard and a team of researchers at Schulich Medicine & Dentistry and the school’s Addiction Research Group. They did not find any evidence of harmful long-term effects in the adult rodents.

However, the researchers noticed that the adolescent rodents were more anxious and more socially withdrawn. The team also observed high levels of dopamine and cognitive disorganization, both of which are present in patients with schizophrenia. Additionally, these changes persisted into early adulthood.

According to Laviolette, their study adds information about the effects of THC exposure in adolescents. People at this age group have a lot of important developmental milestones that make them vulnerable.

“With the current rise in adolescent cannabis use and the increasing THC content in newer cannabis strains, it is critically important to highlight the risk factors associated with exposure to marijuana, particularly during adolescence,” Laviolette added.

The research team also noted the study’s relevance in relation to the legalisation of marijuana.  The government must ensure to make and enact policies that will prevent teens from getting a hold marijuana, the team asserted.