Is regular use of cannabis (aka marijuana) bad for young brains? The short answer is probably “yes.” How severe and how permanent is the damage? – those are the next questions that need to be addressed. Our ability to answer these important questions accurately has been impeded by continuing unreasonable obstacles to scientific research about both the negative and positive effects of cannabis. The issue is becoming more problematic with access to cannabis expanding, Michigan voters in the 2018 election having made it the 10th state in the U.S. to legalize recreational use. Now that it has been made legal in Canada, parents there are understandably worried about the impact on their children, who had already been using it at high levels.
Despite the legal and administrative hurdles, study results are becoming available that shed some light on these issues. An earlier long-term prospective study had shown that the extended use of cannabis multiple times a week before the age of 18 can result in significant permanent declines in multiple cognitive abilities. A new research study with a shorter time frame looked at young people between the ages of 16 to 25 who used cannabis at least once weekly. The study compared the memory and attention functioning of those who stopped using for 30 days with those who continued to use. The good news was that those who stopped using showed an improvement in verbal learning, with most of the improvement occurring within the first week. No improvement, however was found in attention functioning, which previous studies have shown can be negatively affected.
This study raises at least as many questions as it answers. The absence of a baseline prior to the initiation of use limits the conclusions that can be drawn. Ongoing studies will look at whether attention improves with continued abstinence beyond 30 days. What does seem clear is that cannabis cannot be considered a “performance enhancing drug” when learning is involved, with the possible exception of a sub-group of individuals with ADHD.
How does former Attorney General Jeff Sessions fit in here? I suspect that his extreme opposition to marijuana is the reason that the recommendation by the DEA, one year ago, to expand number of sites that are allowed to grow of marijuana for scientific research purposes has not been implemented. His resignation provides an opportunity for this unacceptable situation to be remediated so that we can start getting answers about the nature of this complex substances that remains inadequately understood, despite the thousands of years it has been in use.