Is binge drinking or heavy weed smoking more damaging to the teen brain? In some ways, the answer to this question is simple. Binge drinking is associated with memory blackouts, physical illness, and lasting brain changes. These side effects are not commonly associated with cannabis. However, scientists face strict research barriers when studying cannabis, meaning that quality research on the subject is lacking. Here’s how alcohol and cannabis stack up when it comes to teens.
Cannabis and alcohol are depressants
Both cannabis and alcohol have depressant qualities on the teen brain. One reasons teens are able to learn so much so quickly is because teenage brains are generally more excitable. This excitability helps them quickly respond to stimuli and learn from their environment.
In teenagers, it also happens that the pleasure, reward, fear, and anxiety centers of the brain are more developed than the frontal cortex, which is the thinking and reasoning center of the brain. This means that teens are naturally more pleasure-seeking, and do not have the same capacity to hit the breaks as an adult would.
Both alcohol and the active molecules in cannabis interact with cell receptors throughout the brain, quieting excitability. Yet, as neuroscientist and author Dr. Frances Jensen explains in an interview with NPR, teens may be less sensitive to the drowsy effects of these substances because their brains are more excitable to begin with.
This means that teenagers may end up consuming a lot more alcohol or cannabis to achieve the same level of sedation.
In a November 2016 study published in Translational Psychiatry, teenagers were less likely to feel “stoned” and experienced less psychoactivity when given the same amount of cannabis as adult study participants. Perhaps because of this fact, teens were more likely to go back for more cannabis, while adults were not.
Similarly, binge drinking is extremely popular among young people. In 2015, 7.7 million young Americans under the age of 21 admitted to drinking more than a few sips of alcohol in the previous month. In general, drinking three to four alcoholic beverages for men and three for females within two hours is considered a binge drinking sesh.
For both substances, parents, educators, and medical professionals are concerned that both cannabis and alcohol may interfere with learning and memory during one of the most critical learning periods in human life. Both compounds dampen excitability, which is critical for learning.
Neither alcohol nor cannabis is exactly innocent. Yet, for many consumers, the negative effects of one substance outshine the other. Unlike cannabis, alcohol can cause a complete memory blackout. While your drunken body is involved in all sorts of tomfoolery, heavy doses of alcohol can cause the brain to temporarily lose the ability to record memories.
This can cause a complete amnesia of an event, which is, arguably, more frightening than the hazy forgetfulness from cannabis. According to Dr. Jensen, binge drinking may actually have lasting effects on the teenage brain. She explains,
There are studies that show that binge drinking – which is probably the worst scenario actually – binge drinking can actually kill brain cells in the adolescent brain where it does not to the same extent in the adult brain.
So for the same amount of alcohol, you actually get – you can actually have brain damage, permanent brain damage, in an adolescent for the same blood alcohol level that may not – may cause, you know, bad sedation in the adult but not actual brain damage.
The brew also strongly affects your motor skills, making it difficult to get around and making you more likely to get into physical accidents. Further, underage drinking is associated with increased risks of violence, traffic fatalities, and risky sexual behavior.
Worst case scenario, binge-drinking teens are also at risk of alcohol poisoning, loss of consciousness, and death. Needless to say, none of those things bode well for long-term brain health.
Heavy cannabis smoking
Though there is clear evidence that binge drinking can actually cause brain damage and can lead to a complete amnesia of the party the night before, cannabis is also associated with some negative effects as well.
However, it’s important to note that teen cannabis consumption has been studied significantly less than teen alcohol consumption. Due to legal barriers on cannabis research, scientists have been unable to quickly and comprehensively study the effects of cannabis smoking, especially on the teenage brain.
This could mean that there are some effects that are simply not known yet, that could be important to the health of a developing brain. What is known is that once ingested or inhaled, the active components of cannabis engage special cell receptors called cannabinoid receptors.
It is through these cannabinoid receptors that cannabis has a quieting effect on the brain. This quieting could be beneficial for children with conditions like epilepsy, but Dr. Jensen thinks that the sedative effects of cannabis may be more nuisance than good in a healthy teen brain. She explains:
It turns out that these targets actually block the process of learning and memory so that you have an impairment of being able to lay down new memories. What’s interesting is not only does the teen brain have more space for the cannabis to actually land, if you will, it actually stays there longer.
It locks on longer than in the adult brain. … For instance, if they were to get high over a weekend, the effects may be still there on Thursday and Friday later that week. An adult wouldn’t have that same long-term effect.
By “long-term”, Jensen does not mean that teens feel cannabis high for several days. Rather, a weekend cannabis bender may leave teens feeling fatigued, groggy, unfocused, and forgetful longer than an adult would.
There is also some debate over whether or not cannabis negatively impacts IQ. With alcohol, there is strong evidence that it has a detrimental impact on cognitive learning. Yet, with cannabis, things are less clear.
Some research has found a correlation between chronic teen cannabis and lower cognitive performance. Though, correlation does not aways mean causation.
One study suggests that this association is especially true in consumers that began smoking under the age of 16, who showed signs of brain changes and increased impulsivity. The same correlation was not found in those who sparked up for the first time after 16.
Yet, another recent study suggests that, unlike alcohol, there is no link between cannabis consumption and brain abnormalities in either teen or adult consumers.
Further studies in identical twins have found no correlation between a history of teen cannabis use and IQ. Rather, the authors speculate, confounding environmental factors seem to be at play when it comes to IQ decline in their particular samples.
What about teens predisposed to mental illness?
The evidence thus far suggests that binge drinking is worse for the average teen brain than heavy cannabis consumption. However, there is one particular risk group that may be hit particularly hard by heavy use of either substance.
Thus far, no research has demonstrated a causal correlation between cannabis consumption and the development of psychosis or early-onset schizophrenia. At best, research suggests that there is an association between something in the cannabis environment and the risk of having a psychotic episode.
However, this relationship is significantly more complicated than one might think. Some evidence suggests that chronic, teen cannabis consumers who have a predisposition for psychotic disorders may be more likely to develop early-onset psychosis.
Unfortunately, this research has yet to prove whether or not cannabis was the trigger, whether or not there is an underlying health or genetic factor, or whether environmental factors contributed to the connection.
Additional research on the topic suggests that those likely to experience cannabis-induced psychosis may have a particular genetic mutation. Back in 2016, British researchers discovered that consumers who were more likely to report symptoms of paranoia, anxiety, and other psychotic-like experiences had the same genetic mutation.
Should this research hold true with further study, it seems as though there may be particular groups of people that simply don’t do well with cannabis. The only way to safely determine the role both cannabis and alcohol play in brain development and mental health is to perform more research.