What does weed do to the teenage brain?

Worried parents have been warning their teenage children about the dangers of marijuana for many years, and their teenagers have been ignoring those worries for just as long. Parents worry about the effects of weed on the developing brains of teenagers, whereas many teenagers, especially now cannabis is legal in so many places, don’t feel like listening. 

The often exaggerated perils of cannabis, such as the risks of brain damage, addiction, and even psychosis, haven’t helped teenagers to take their parents’ concerns very seriously. Knowing that their parents’ dire threats of ending up addicted to much harder drugs or ending up damaging their growing brains are not quite true is a fast way to set off the classic skepticism of teenagers for whatever adults are suggesting. However, the basic facts are enough to make parents worry. 

It is known that being high can impair the attention span, memory, and ability to learn. Some stronger varieties of marijuana can make users physically ill or delusional, which is why it’s so important to only use a legal weed store in Vernon or wherever you are, so you know what you’re getting. Whether or not weed actually causes lasting brain damage is less clear. 

Studies in adults found that nonusers outperform users of marijuana in tests of motor skills, attention, memory, and verbal abilities, but some of these results could be put down to the effects of having cannabis still in the body, or withdrawal effect from abstaining while taking part in the study. Some studies seem to suggest that when participants stop using weed for longer periods, their performance on cognitive tests doesn’t vary much from those who don’t use at all. 

During adolescence, the brain matures in a few ways that strengthen executive functions, like emotional self-control. Some research suggests that cannabis use could disrupt this maturation. 

Some more recent studies show that cannabinoids that are manufactured by our own nerve cells have an important role to play in wiring the brain during adolescence. These cannabinoids regulate appetite, sleep, emotion, memory, and movement. During teenage years, there are big changes in the concentration of those endocannabinoids, which is why many scientists, and therefore parents, worry about the impact of weed on the teenage brain. 

Brain-imagine studies support these worries. A number of smaller studies have seen some differences in the brains of those who smoke weed on a regular basis. These differences include altered connectivity between the hemispheres, less efficient cognitive processing in adolescent users, and a small amygdala and hippocampus. These structures are involved in regulating emotion and memory. 

Some more evidence can also be taken from research in animals. When rats are given THC, which is the chemical in marijuana that gets you high, they show cognitive difficulties if they are exposed to the THC during their puberty. However, this doesn’t happen if they are exposed as adults. 

The belief that damage is permanent also has some holes. Studies in rats usually use much higher doses of THC than any weed users would absorb, and rodents are only adolescents for a couple of weeks, nothing like humans. With brain-imaging studies, the samples are usually small which makes the causality uncertain. It is difficult to discount other factors, like childhood poverty, abuse, and neglect, which all also impact brain anatomy, and which often correlate with substance abuse. 

To really know how much weed affects the teenage brain, scientists would need to study children from childhood into early adulthood. An American study, the Adolescent Brain Cognitive Development is now being carried out by the National Institutes of Health and ought to help with this. The ten-year project will follow 10,000 children from age nine or ten, looking at brain scans, genetic and psychological tests, academic records, and surveys. This study should help to answer some of the questions into what role marijuana might play in brain development. 

If it does turn out that weed doesn’t pose any direct danger for most or even all teenagers, marijuana is not a benign thing. If teenagers choose to spend time getting high instead of going to classes, they will miss out on important social and intellectual stimulation that the adolescent brain is tuned in to. The teenage years are important for maximizing the capacity to understand complex situations. Teens are literally building the brainpower. On average, adolescents who use weed are unhappier and achieve less than those who don’t. 

While the answers aren’t clear, all this does show the importance of understanding the choice you’re making. Always obtain marijuana from a weed store, who can help you make a safe choice.