A brain protein associated with depression and Alzheimer’s in young marijuana users has now also been linked to stress and anxiety.
Previous studies have shown that marijuana can reduce stress and quell anxiety in adults. New Canadian research indicates the same might not be true for adolescents. Instead, young cannabis users often develop a brain protein associated with stress and anxiety, according to the study.
The research, which was published in the JAMA Psychiatry journal Wednesday, provides another important clue to how marijuana affects the developing brain. However, the scientists behind the study were quick to state their findings don’t establish a clear link between cannabis use and anxiety.
“Cannabis is the most commonly used illicit drug in the world but we know very little about the impact it has on the brain, especially in young users whose brains are still developing until the age of 25,” Dr. Romina Mizrahi, the study’s lead author, said in a statement. “These findings are an important step forward, but more studies are needed to better understand the role of cannabinoids and neuroimmune signaling.”
Utilizing technology to scan the brains of 24 young long-term cannabis users and 27 young non-users, scientists found that the cannabis users had higher levels of brain protein TPSO. In prior research, TPSO has been associated with depression, Alzheimer’s disease, and brain inflammation. Furthermore, young subjects with cannabis use disorder, which is qualified by people who develop an overdependence on marijuana, reported the highest levels of this brain protein.
It's important to consider that this study does not suggest a correlation or causation between cannabis use & stress/anxiety, but that there is an association via a specific protein 'TSPO'. Further research & evaluation will be needed to understand these findings.
— CAMH Research (@CAMHResearch) September 18, 2019
This discovery shocked scientists, as they had hypothesized the exact opposite. When comparing cannabis users and non-users, researchers expected that marijuana users would have low levels of “neuroinflammation biomarkers,” including the TPSO brain protein. That’s because marijuana use, as referenced above, is often associated with reducing inflammation.
“Having a hypothesis disproven this clearly is rare, but this is a strong finding,” Mizrahi told CTV News in a statement.
Next, Mizrahi and her team will examine whether or not marijuana abstinence would cause the elevated levels of TPSO brain protein to return to normal. Previous research has shown that marijuana legalization does draw teenagers to use cannabis, but instead lower youth marijuana use rates.