BlackburnNews.com file photo of someone smoking marijuana.

Teen Pot Use Effects Can Be Reversed

With Canada set to legalize pot next summer, Western University researchers have made a breakthrough when it comes to reversing the negative effects caused by adolescent usage of the drug.

Using pharmaceuticals, researchers believe they can counter the psychiatric effects of THC, the psychoactive chemical found in marijuana. That could stop the development of psychiatric diseases, such as schizophrenia, in adulthood for chronic adolescent marijuana users.

The study, published online Tuesday in Scientific Reports, found THC exposure modulates the activity of a neurotransmitter called GABA in the prefrontal cortex region of the brain. Researchers zeroed in on GABA because of it’s been known to show clinical association with schizophrenia.

“GABA is an inhibitory neurotransmitter and plays a crucial role in regulating the excitatory activity in the frontal cortex, so if you have less GABA, your neuronal systems become hyperactive leading to behavioural changes consistent with schizophrenia,” said Justine Renard, post-doctoral fellow who co-led the study with Steven Laviolette, professor at Western’s Schulich School of Medicine & Dentistry.

Western’s Schulich School of Medicine & Dentistry Professor Steven Laviolette and post-doctoral fellow Justine Renard. Photo courtesy of mediarelations.uwo.ca.

Western’s Schulich School of Medicine & Dentistry Professor Steven Laviolette and post-doctoral fellow Justine Renard. Photo courtesy of mediarelations.uwo.ca.

The reduction of GABA as a result of THC exposure in adolescence caused the neurons in adulthood to not only be hyperactive in this part of the brain, but also to be out of synch with each other, according to the study. This loss of GABA in the cortex caused a corresponding hyperactive state in the brain’s dopamine system, which is commonly observed in schizophrenia.

But by using drugs to activate GABA in a rat model of schizophrenia, researchers were able to reverse the neuronal and behavioural effects of the THC and eliminate the schizophrenia-like symptoms.

“What this could mean is that if you are going to be using marijuana, in a recreational or medicinal way, you can potentially combine it with compounds that boost GABA to block the negative effects of THC,” said Laviolette.

Moving forward, Laviolette and Renard intend to examine how combinations of cannabinoid chemicals with compounds that can boost the brain’s GABA system may serve as more effective and safer treatments for a variety of mental health disorders, such as addiction, depression and anxiety.