How Substance Use Affects Teen and Young Adult Development
Adolescence and young adulthood are transformative stages of life. These years help shape a person’s identity, influence social relationships, and impact how they view the world around them. Most importantly, this period is critical for brain and physical development. Unfortunately, young people face a variety of factors that can negatively affect them during these formative years. One of the most significant influences is substance use.For this reason, it is important to understand how substance use and misuse during adolescence and young adulthood can have lasting negative effects on physical, emotional, behavioral, and cognitive development.
The Effects on the Developing Brain
The human brain begins to develop approximately three to four weeks after conception, when the neural tube forms and closes. During adolescence, a stage within what the University of Cambridge refers to as “the second epoch of the brain,” the brain’s communication networks become increasingly refined, supporting enhanced cognitive development. The brain continues to develop and does not fully mature until the early 30s.1
Substance use can affect areas of the brain responsible for essential functions and may also contribute to compulsive drug-seeking behaviors that can lead to addiction. The parts of the brain most affected by substance use include the basal ganglia, the extended amygdala, and the prefrontal cortex.
– The Basal Ganglia
This part of the brain plays a key role in the brain’s reward circuit, which influences motivation, the pleasurable effects of healthy activities, and habit formation. Substance use overstimulates this circuit, producing the feeling often referred to as a “drug high.” Over time, repeated substance use causes the brain to adapt to the presence of the drug, making it more difficult for individuals to experience pleasure from everyday activities without it.
– The Extended Amygdala
This part of the brain regulates emotions such as anxiety, irritability, and unease. Through continued substance use, this brain circuit becomes increasingly sensitive over time. As a result, individuals with a substance use disorder may continue using substances not to get high, but to gain temporary relief from these uncomfortable feelings. This process is commonly associated with withdrawal.
– The Prefrontal Cortex
The prefrontal cortex is the last part of the brain to fully develop, which makes adolescents and young adults particularly vulnerable to the negative effects of substance use. This region is responsible for critical functions such as decision-making, problem-solving, impulse control, and reasoning. Because the prefrontal cortex is still developing during adolescence and young adulthood, substance use can increase the risk of long-term challenges with attention, memory, and other cognitive abilities, which can impact social interactions and academic performance.
The Effects on Behavioral Health
Understanding how substance use affects different parts of the brain helps illustrate its direct impact on young people’s behavioral health. Because substance use can disrupt the development of the prefrontal cortex, individuals may have difficulty making rational decisions, controlling impulses, and regulating their emotions. This can lead to increased emotional volatility and greater engagement in risky behaviors.
For young people experiencing behavioral health conditions such as ADHD, depression, or anxiety, substance use and misuse can worsen symptoms and make these conditions more difficult to manage.
The Effects on Physical Health
Substance use and misuse can also have long-term negative effects on an individual’s physical health, especially during critical developmental years.
One way substance use affects physical health is by disrupting sleep, which plays a vital role in supporting healthy physical growth, brain development, emotional regulation, and overall well-being during adolescence and young adulthood. Substance use can interfere with deep sleep and REM (rapid eye movement) sleep, leading to fatigue and impairing cognitive function. Other substances, such as stimulants, can overstimulate the nervous system, making it more difficult to fall and stay asleep.
Substance use also impacts many of the body’s essential systems and organs. For example, alcohol misuse can cause permanent liver scarring and may lead to liver disease. Smoking tobacco or cannabis, as well as vaping, can damage the lungs and increase the risk of cancer. Stimulants can raise blood pressure and increase the risk of stroke and heart attack.
How You Can Support the Young People in Your Life
Substance use and misuse can be a challenge for young people, but it is not something they have to face alone. During these critical developmental years, it is important for them to have trusted individuals in their lives who are willing to recognize their struggles, listen without judgment, and connect them with appropriate resources and support. If substance use is affecting a young person you know, or if you are a young person facing these challenges yourself, we encourage you to seek help.
At Teen Health Connection, we offer behavioral health services, health education programs, and referral resources designed to support adolescents and young adults as they navigate different challenges in their lives. If you or someone you know needs support, reach out to Teen Health Connection to learn more about the resources available and take the first step toward a healthier future.
References:
- Quinde Reyes, M., Jiménez Bautista, F., Soria-Miranda, N., Oleas, D.,
Mascialino, G., Vera Ponce, I., & Rodas, J. A. (2025).
Family and personal factors predisposing adolescents to substance abuse
in high-risk urban areas.
PLOS ONE, 20(11), e0334072.
https://doi.org/10.1371/journal.pone.0334072 - University of Cambridge. (2025, November 25).
Scientists identify five ages of the human brain over a lifetime.
University of Cambridge.
https://www.cam.ac.uk/stories/five-ages-human-brain - National Institute on Drug Abuse. (2020, July 6).
Drugs and the brain.
U.S. Department of Health and Human Services, National Institutes of Health.
https://nida.nih.gov/publications/drugs-brains-behavior-science-addiction/drugs-brain - Miller, C. (2026, February 20).
Teen substance use & mental health disorders.
Child Mind Institute.
https://childmind.org/article/mental-health-disorders-and-substance-use/ - Recovery Research Institute. (n.d.).
Teen use of alcohol and cannabis for sleep: Helpful or harmful?
Recovery Research Institute.
https://www.recoveryanswers.org/research-post/teen-use-alcohol-and-cannabis-sleep-helpful-harmful/ - Addiction Center. (2025, June 15).
Health effects of teen substance abuse. – Addiction Center.
https://www.addictioncenter.com/teenage-drug-abuse/health-effects-teen-substance-abuse/
