Teenagers and young adults sometimes succumb to the peer pressures of recreational drug use. Marijuana in particular is popular among students from grades eight to 12. It is a mixture of dried flowers, leaves, seeds, and stems from the hemp plant also known as Cannabis sativa. Marijuana is known to reduce pain and induce feelings of euphoria and relaxation—in other words, it helps people get high. On the other hand, the drug can be very addictive and is also thought to affect a teenage brain that is still in development.
In a new study published in the journal Cerebral Cortex, researchers from Western University in Ontario, Canada, have found that adolescents who smoke marijuana can develop schizophrenia-like changes in the brain.
As a result, marijuana can lead to long-term cognitive problems. Large marijuana doses are also thought to induce delusions, hallucinations, and a loss of personal identity. The intoxicating effect in marijuana is caused by the chemical delta-9-tetrahydro-cannabinol—also called THC.
The research team sought to examine the long-term effects of THC on the teenage brain when TGC was given to adolescent rats. For the study, the researchers carried out tests that relate to behavior that is common in schizophrenia and other neuropsychiatric disorders, including cognition and motivation, anxiety levels, cognitive disorganization, and social interaction.
The team then compared the long-term THC effects in adults and adolescents by using an in vivo neuronal electrophysiological model, and the combination of molecular and behavioral analysis. The results found identical neuronal, molecular, and behavioral changes to schizophrenia.
When the adolescent rats were exposed to THC, they demonstrated features related to schizophrenia such as increased cognitive disorganization, abnormal dopamine levels, and greater anxiety. These brain changes continued early into adulthood; however, the adult rats didn’t show any harmful, long-term effects.
The adolescent rats also demonstrated various altered prefrontal cortical molecular pathways, which is constant in a key characteristic of schizophrenia called subcortical DAergic dysregulation.
Twenty-three states and Washington, D.C. have legalized cannabis, mainly for medicinal purposes, but the use of recreational marijuana is legal in Colorado, Alaska, Oregon, Washington and the District of Columbia.
Approximately 15% of eighth graders have tried marijuana and one percent is believed to use the substance every day, according to data from the National Institute on Drug Abuse (NIDA).
“Health policy makers need to ensure that marijuana, especially marijuana strains with high THC levels, stays out of the hands of teenagers,” explained lead study researcher Steven Laviolette.
It is not the first study to demonstrate the effects of regular marijuana use on the teenage brain. For instance, a study presented at the American Psychological Association’s 122nd Annual Convention found that frequent marijuana use can produce negative effects on the brains of young adults and teenagers such as a decreased IQ, poor memory and attention, and cognitive decline.
Marijuana can also lead to side effects like fear and panic, especially when the dose is potent. Other short-term effects include distortion of perception, memory and judgment loss. Smoking marijuana has also been linked to an increased heart rate, respiratory problems, and other mental health conditions like depression.
Sources for Today’s Article:
Renard, J., “Adolescent Cannabinoid Exposure Induces a Persistent Sub-Cortical Hyper-Dopaminergic State and Associated Molecular Adaptations in the Prefrontal Cortex,” Cerebral Cortex, 2016, doi: 10.1093/cercor/bhv335.