Before I started studying the brain, I had a pretty laissez faire attitude towards marijuana use. If you had asked me, even five years ago, how I intended to educate my children in drug use, I would have espoused an “everything in moderation” attitude. Luckily, I started to learn more about the brain before my son was old enough to be impacted by my naive attitude.
Youth may be a time of experimentation, but sometimes experimenting is more harmful for young people than it would be for a fully developed adult. Research indicates that marijuana use falls into this category.
According to the Natural Institute of Drug Abuse, 34.9 percent of high school seniors report using marijuana in the past year. Use, especially at such a young age, is associated with major depressive disorder and cognitive deficits. However, depression, in and of itself, is also linked to cognitive decline.
A recent study investigated cognitive function and connectivity in depressed subjects who don’t use marijuana, compared to those that do. The researchers also differentiated between those who started using early in life, and those who started using later.
74 young people were categorized amongst four groups:
- Healthy control
- Frequent Marijuana users who had depression
- Frequent Marijuana users who did not have depression
- Depressed individuals who did not use marijuana
They were also sub-categorized into those who had started using marijuana before the age of seventeen and those who started later. Subjects were sent through a battery of tests and their default mode network (DMN) brain connectivity was assessed with brain scans.
The results? Marijuana use did not lesson the psychiatric effects of depression. Moreover, in some areas of brain function, depressed marijuana users deteriorated more than their non-marijuana using peers. Early onset marijuana use, independent of depression, resulted in impaired cognitive functioning and a lower IQ score.
It turns out, our parents were right. Marijuana use isn’t good for kids. Now we know why.