How Illicit Drugs Affect Brain and Growth Development

How Illicit Drugs Affect Brain and Growth Development

Illicit drugs aren’t good for the human mind in general, but especially when the brain is growing rapidly, such as it does in puberty, illicit drugs are especially problematic.

Stunting growth in the brain’s emotional and cognitive sectors is dire for the human body’s most complex organ. Here is how illicit drugs affect the human brain during growth development.

How the Brain Works

how the brain worksThe brain is the most complex organ in the human body. It is like a complicated computer, but instead of silicone and electricity, your brain uses synapses and neurons to transmit information. Neurons are arranged into vast web networks across the brain, and your brain is constantly rewiring and reprogramming itself as you learn and remember.

Different parts of the brain deal with specific systems or areas of the body. Your cerebellum controls your musculoskeletal structure, while your amygdala handles all your emotional responses to stimuli. As these areas connect, your brain spawns a vast system of neurons, reaching all parts of your body through the nervous system.

Using drugs or alcohol disrupts these critical connections in your brain. The long-term effects can cause the deterioration of many systems, not just the brain.

Adolescence and Brain Development

The brain’s growth patterns in adolescence – roughly early teens to mid-20s – are uneven at best. The first areas to grow are those that control physical movement (cerebellum), emotional development (amygdala), and inspiration (nucleus accumbens). The area that governs impulse control and good decision making, the prefrontal cortex, develops later on.

When observing teens, it’s easy to see that this uneven development pattern affects certain behaviors. Teenagers often have difficulty controlling strong emotions, making reasoned decisions, and not giving in to their impulses with little planning. Since the teen’s reasoning develops last, it is clear how some teens fall into risky, dangerous situations without much forethought.

In these formative years, the teen’s brain is much more susceptible to damage from outside sources, so using illicit drugs comes with more severe consequences if the user is a teenager. One of the reasons behind this increased risk of damage is myelin.

Myelin is the covering that protects neurons in your brain, but this covering on teen’s neurons is not as substantial as they are on adult neurons. The thinner shielding properties of teens’ myelin can send louder messages throughout the brain’s delicate network.

How Drugs Affect the Brain

Illicit drugs disrupt how neurons receive and emit messages with neurotransmitters. With opioids like heroin, the illegal substance molecules mimic naturally occurring neurotransmitters in the body, so they can latch onto and activate neurons in the brain. Because of these unnatural additives to the brain’s delicate chemistry, abnormal messages bounce around your neural network.

Other drugs, like cocaine or amphetamines, work with the brain differently. Known as stimulants, these drugs can cause the brain to release excessive amounts of neurotransmitters like dopamine, which causes an unnatural response in the brain.

Most long-term use of illicit substances causes addiction and other severe health problems, so getting help as soon as possible is a crucial step to recovery.

Illicit Drugs and the Brain’s Growth Development

There are three major groups of illicit drugs – depressants, stimulants, and hallucinogens. Here is how each of these groupings affects your brain’s chemistry.


This group of drugs causes your brain and body systems to slow down. When taking depressants, your body temperature goes down, and your breathing and heart rate slow down.


These types of drugs cause the brain to become overly excited and function very quickly. Your heart races, breathing speeds up, and your body temperature rises when you take stimulants.


These drugs produce auditory or visual hallucinations that aren’t based on reality.

When you take these types of illicit substances as an adult, you risk long-term addiction issues and other health risks, depending on which one you’re using. Teens face a higher susceptibility for long-term damage because their brains are still growing and developing.

Illicit Drugs Effects on Growth and Development

Different Effects on Adults’ and Teens’ BrainsIt’s not just the brain that’s affected by any drug use; other organs and systems also become irrevocably altered with long-term substance abuse. There are some concerns that cannabis can trigger early puberty in boys, which may result in minimal growth patterns.

Alcohol also inhibits sexual and growth hormone production, especially in adolescents, so stunted growth and short limbs may be a result of early drinking. Lowered bone density paves the way for weaker bone density, another symptom of early alcohol abuse.

Different Effects on Adults’ and Teens’ Brains

All addictive substances light up the reward pathways in a human’s brain, which is why the substance is addictive as the human always wants more of the rewarding feeling. However, in a teen’s developing brain, these reward pathways are just becoming substantiated, so illicit drug use can often disrupt the delicate balance.

Certain illicit substances release dopamine in the body, flooding the user with feelings of positivity and euphoria. What makes addictive drugs so dangerous is that they override the natural dopamine release in your body, causing a flood. You then become hooked on this excess of warm, rosy feelings and crave it. In a developing brain, this can set the stage for long-term drug dependence.

The Final Say

If you or a loved one struggles with drug addiction, especially if that person is young enough that their brain is still developing, you need to address the issue immediately before it gets any worse.

The brain is a marvelous organ and, when it’s growing, it is making new connections and networks daily. Any illicit drug use when the brain is in its developmental stage could result in permanent changes. It’s never too early or late to find the help you need. Call us today at Right Path Addiction Centers to begin the journey to recovery.

Written by Sergey Zhitar, MD Medical Director

Native of Moldova, Dr. Zhitar is Board Certified in Addiction Medicine as well as Internal Medicine and completed his training at UPMC Shadyside, Pittsburgh, PA in 2000.