Teen Marijuana Use: Brain and Developmental Risks

Marijuana is the most commonly used illicit drug in the United States, though the term “illicit” does not always apply. Twenty-three states have already passed measures approving marijuana for medicinal use, and five have legalized recreational use for individuals over the age of 21.

These measures have been subject to their share of controversy. One major concern is that as in the case with alcohol, legal age limits will do little to impede young adults from using the drug. Adolescents and teens are particularly vulnerable. A growing body of research suggests that using marijuana frequently at a young age can disrupt brain development and ultimately create lasting damage in teens.

Marijuana’s Cloudy Effects

In a medical setting, marijuana has demonstrated an ability to provide relief in patients suffering from seizures, pain, and nausea associated with chemotherapy. For these individuals, using cannabis as directed can improve their quality of life. However, the compound believed to be responsible for this relief, Cannabidiol, has been the subject of some debate. Recently, the Senate recommended an $800,000 grant to the Institute of Medicine to delve more deeply into the risks and benefits of medical marijuana.

Experts do agree that the compound responsible for marijuana’s trademark high, THC, is associated with some negative outcomes. In the short term, research shows that marijuana use impairs some functions like memory, learning, decision-making, and attention span. These ill effects can last for days after the initial high. Heavy or prolonged marijuana use in the teenage years has been linked to a higher rate of school dropout, lower grades, and increased dependence on government programs such as welfare and unemployment, and lower life satisfaction.

Marijuana and the Young Brain

There are few long-term studies that follow the effects of marijuana on young people before and after their first encounter with cannabis, but emerging research shows worrisome outcomes for those who start using cannabis at a young age. A Duke University psychologist collected data from 1,000 New Zealanders born in 1972, who answered questions regarding marijuana use at the age of 18, 21, 26, 32, and 38. They also agreed to neuropsychological testing at 13 and 38. The research team found that persistent marijuana use starting at a young age was associated with a lower IQ, How Marijuana Affects The Adolescent Braineven after applying controls to compensate for variables such as education level. Those who reported continued marijuana use throughout at least three levels of the study experienced a drop in neurological functioning equivalent to six IQ points. That’s about what you would expect to see after exposure to lead.

Researchers believe that young adults are uniquely susceptible to the effects of drug use since their brains are still under construction. During the period of adolescence, brains are believed to be susceptible to long-lasting damage from drug exposure. Notably, the frontal cortex, which is partially responsible for planning, making decisions, judgment, and our personality – is still immature until the early 20s.

The endocannabinoid system is also immature in teens, which is responsible for the physiological mechanisms that respond to THC. This system is also responsible for several different higher functions, such as cognition, stress response, and emotional regulation. Prolonged or repeated exposure to marijuana slows cellular and developmental activity in this system.

Your Brain on Drugs

An increasing number of studies point to evidence of brain changes in teens who smoke marijuana regularly. A meta-analysis of 43 studies of the effects of chronic cannabis use on the brain found consistent evidence of altered neurological activity and brain abnormalities among marijuana users. Eight of these studies involved adolescents, and those studies all suggested that the functional and structural brain changes associated with marijuana use begin to occur shortly after a teen’s first encounter with marijuana. What’s more, many of these changes were still evident one month after abstinence from marijuana.

Some brain abnormalities are associated with cognitive deficits. For example, one study found that regular, heavy marijuana users – defined as smoking five out of the past seven days and in excess of 2,500 times total – experienced damage to their white matter, which is responsible for communication along neural pathways. Those changes were associated with an increase in impulsivity.

These changes were reported only in the heaviest users, at least five times in the past week. But other studies have pointed to changes in the brain, even in those who use less frequently. A study from Massachusetts General Hospital found brain changes in 18-25-year-olds who smoked at least once a week and were not dependent. Compared to those who didn’t use at all, users had notable differences in the shape, volume, and density of gray matter in the amygdala and nucleus accumbens, which are involved with memory and decision-making, respectively.

Emotional and Mental Effects

In teens, marijuana can affect both mental and physical health. Marijuana use in the adolescent years is associated with a two-fold increase in developing anxiety and depression, and teens that use regularly are three times more likely to experience suicidal thoughts compared to those who didn’t smoke at all. Additionally, those who smoke marijuana are at an increased risk of developing schizophrenia later in adolescence.

In sum, the areas of the brain responsible for judgment, decision-making, and emotional control are still in development. Exposure to marijuana, even in small doses, can lead to altered brain structure and function over time. Researchers are beginning to see a trend emerging in teens that regularly use marijuana – they are more likely to be depressed, anxious, unemployed, and perform poorly in school. This provides a compelling call to action for parents, legislators, and public health officials to keep marijuana away from adolescents.

Treatment for Marijuana Addiction

If you or a loved one are experiencing any signs of marijuana addiction, know that help is available. The admissions counselors at The Treatment Center understand the difficulties associated with addiction, and the empathetic staff offers individualized treatment for marijuana addiction — and multiple addictions if necessary.

If You Suspect That Your Teen Might Be Abusing Marijuana, Get Help Today.

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