By the end of 8th grade, one of every four Cambridge teens has used alcohol. Most of them get the alcohol from a parent, another adult, or from home without anyone knowing.
Parents can keep their children safe by talking with them about the reality of alcohol and marijuana and setting boundaries. The Reality Check campaign helps parents be clear with their teens about underage drinking and drug use, and connect with other parents and resources.



You might hear teens (and even other parents) say that alcohol and marijuana aren’t “that bad” or “OK in moderation.” However, substances like alcohol and marijuana are especially dangerous for teen brains – which are still growing and developing until about age 25.

Teens have a higher risk for addiction than adults when exposed to substances like drugs and alcohol. This risk is due to teens having:

  • Greater reward sensitivity – the same things that feel “good” to adults feel “REALLY GOOD” to teens
  • Incomplete networking of the brain – making teens more likely to participate in risky behaviors and have “mental clumsiness”
  • Rapid/faster learning (neuroplasticity) – the brain learns that being high is “normal”

Additionally, the risk of alcohol and marijuana dependence increases when the age of first use decreases. For example, a person who drinks for the first time at age 14 or younger is about 7 times as likely to experience alcohol dependency or abuse than a person who has their first drink at age 21 or older (14.8% vs. 2.3%) (SAMHSA, NSDUH, 2013).




Marijuana enters the lungs through inhalation -> Goes into the blood stream -> Reaches the brain

THC, the main psychoactive ingredient in marijuana, binds to receptors in different parts of the brain and affects the teen’s: Memory, Conversation, Distance perception, Ability to coordinate movement, Brain coordination, Attention, Vision, Sense of time.

Marijuana use may also lead to chronic attention deficit, impulsivity, and inability to learn from previous mistakes. It can also make teens more vulnerable to drug use overall.

The human body produces a chemical called anandamide, which controls the release of many different neurotransmitters (chemical messengers) in the brain.
The chemical structure of THC (the main psychoactive ingredient in marijuana) looks very similar to the chemical structure of anandamide.

When a teen uses marijuana, the THC is able to “fool” the brain’s receptors into sending out messages to be filled or “get a fix.”
The developing brain perceives filled receptors to be normal, so it wants to keep them filled – making it much harder for teens to quit using.


This information was adapted from a presentation by Traci Brooks, MD, Director of Adolescent Medical Services at the Cambridge Health Alliance.

Learn more about the teen brain and why kids act the way they do.