The human brain experiences profound developmental changes during the teenage years and, while these changes are underway, remains extraordinarily sensitive to positive or negative influences from the environment. Trauma, chronic stress and use of psychoactive substances are among the factors that can negatively affect brain development in young people.
By the time they finish high school, almost half of American teenagers will have experimented with cannabis at least once1. In fact, in 2017 almost three percent of 8 graders and six percent of 12 graders reported having used cannabis daily2. These are not small numbers: according to the National Center for Education Statistics, in 2017 more than 15 million students enrolled in grades 9 to 123, which translates into 450,000 to 900,000 daily cannabis users in the same age bracket.
What do we know about the impact of cannabis on the adolescent brain? Surprisingly little. A number of published studies give us pause, but much remains to be learned. Filling this knowledge gap is ICAL’s primary mission.
The psychoactive chemical in cannabis, THC, works by mimicking a small family of brain neurotransmitters called ‘endocannabinoids’. These chemicals are crucial for many brain functions and recent discoveries suggest that they may control sociality and playfulness, two of the most salient features of adolescence.
These new findings raise a series of troubling questions. If the endocannabinoids are important in adolescence, as research suggests, can exposure to THC change this neurotransmitter system in a persistent way? What alterations at the level of molecules and cells underpin these changes? And, most importantly, what are their enduring consequences on learning, memory and emotion?
These are some of the key questions that ICAL, with the fundamental support of the National Institute on Drug Abuse, intends to address. Answering them will directly benefit the scientific community and the public, and will help establish a solid evidence-based ground for policy decisions concerning the medicinal and recreational uses of cannabis.
1 Johnston L, O’Malley P, Miech R, Bachman J, Schulenberg J. Monitoring the Future National Survey Results on Drug Use: 1975-2015: Overview: Key Findings on Adolescent Drug Use. Ann Arbor, MI: Institute for Social Research, The University of Michigan; 2015.