Researchers believe a severe mental illness that affects a person’s behavior, emotions and thought processes is caused by a specific genetic interaction with different environmental factors.
A research study conducted by a team of researchers at the Tel Aviv University and Johns Hopkins University reveals that cannabis use during the teen years may trigger schizophrenia in people, who are already prone to the mental disorder.
“Our research demonstrates that cannabis has a different risk on susceptible versus non-susceptible individuals,” said coauthor of the study Dr. Barzilay. “In order words, young people with a genetic susceptibility to schizophrenia – those who have psychiatric disorders in their families – should bear in mind that they’re playing with fire if they smoke pot during adolescence.”
The research team genetically modified mouse models with the mutant DISC-1 gene to make them susceptible to schizophrenia. The mice were then exposed to tetrahydrocannabinol (THC), which is the principal psychoactive compound in cannabis. The susceptible mice like adolescents were discovered to be at a much higher risk for long-lasting brain defects linked to the onset of schizophrenia.
Four different groups of mice were utilized in the study: genetically susceptible and not exposed to cannabis; genetically susceptible and exposed to cannabis; genetically intact and exposed to cannabis; genetically intact and not exposed to cannabis. The genetically susceptible mouse models were the only group to develop biochemical and behavioral brain pathologies associated with schizophrenia following exposure to cannabis, neurological biochemical analyses and behavioral tests showed.
The protective mechanism in cannabis that triggers the specific gene was also identified in non-susceptible mice.
Lead author professor Dani Offen said, “This mechanism involves the unregulation of a protective neurotrophic factor, BDNF, in the hippocampus. We showed in the study that if we artificially deliver BDNF to the genetically susceptible mice, they could be protected from the deleterious effect of THC during adolescence.”
The researchers note that the identification of the protective mechanism might serve as a base for future development of compounds that are capable of reducing the harmful effect of cannabis on brain development. It is also imperative for young people at risk for mental disorders – have a family history of mental disorders – should take precaution against cannabis during the teenage years.
The study was published in the journal Human Molecular Genetics on April 11, 2017.