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National Drug and Alcohol Facts Week: The Effects of Illicit Drugs on The Major Organs of Teens


This article follows up on the information presented in our post National Drug and Alcohol Facts Week: The Latest Data on Adolescent Drug Use. In that article, we offered a string of useful statistics about teens and drug use. We asked you to think about how to use this latest round of data from the National Institute of Drug Abuse (NIDA) to help your teen. We’re doing the same with this article: presenting data and asking you to use it to help your teenager.

The latest statistics from the 2017 National Survey on Drug Use and Health (NSDUH) show that close to half of the adolescents in the U.S. will try an illicit drug by the time they’re seniors in high school. In light of this fact, we advise an open and honest discussion with your teen about the health dangers associated with illicit drug use. Our position is this: the more knowledge they have about drugs ahead of time, the more likley they are to make a mature decision when the time comes.

And that time will come.

So, have that talk, whether or not you think your teen might experiment with drugs. Read the information below and share the facts with your teenager. If they do choose to use illicit drugs, then they’ll know exactly what they’re signing up for.

The Health Consequences of Illicit Drug Use

Most people, teenagers included, know that long-term drug use can damage the body. What most people don’t know are the specifics. They’re unaware which organs each drug affects, what the effects on those organs are, and how serious those effects might be. In this article, we’ll address those questions, starting with the most commonly used illicit drug, marijuana. After that, we’ll discuss amphetamines and opiates, the next most commonly abused drugs identified in the NSDUH report. We’ll discuss what organs are affected and list the primary risks associated with each organ for each drug. We left cocaine off the list, since the negative effects of cocaine closely mirror those of amphetamines.


The Brain
  • Short-term marijuana use can have negative effects on the areas of the brain responsible for memory, learning, decision-making, attention, motor coordination, and emotions.
    • Short-term heavy marijuana use can cause acute problems with memory, attention, and learning.
    • In rare cases, high doses of marijuana can induce paranoia and psychosis.
  • Long-term marijuana use can have negative effects on attention, memory, and learning. These effects can be compounded when marijuana use starts during adolescence.
    • The extent of marijuana’s impact on the developing brain depends on several factors:
      • The amount of THC (the psychoactive ingredient in marijuana) present in the marijuana used
      • How often marijuana is used
      • Age at first use
      • Simultaneous use of other substances such as alcohol or tobacco
A Note About The Marijuana Data

Evidence showing exactly how and why marijuana changes the brain and affects memory, attention, cognition, and learning is inconclusive. Also, evidence showing exactly how long changes in the brain resulting from marijuana use persist is inconclusive. To quote one of the more recent studies on the effects of marijuana on brain physiology and function:

“All in all, these findings suggest that chronic marijuana use results in complex neuroadaptive processes. Future studies are needed to determine whether these changes revert back to normal following protracted abstinence from marijuana use.”

What that means to us is that there’s solid evidence showing marijuana use changes both the structure and function of the brain, and the brain may or may not return to normal when marijuana use ends. When under the influence of marijuana, the brain can perform many of the tasks a person not under the influence of marijuana can – and perform them within standard margins of error – but the way it performs those tasks is unique. That’s the “complex neuroadaptive processes” part of the quote above. That’s also the part scientists have yet to pin down. However, they do know those changes – though not totally defined at this point – are more pronounced when use begins early and when the use is heavy and prolonged.

The Heart
  • Marijuana increases heart rate and blood pressure for at least an hour after consumption in any form.
  • A 2017 study analyzed data from over 20 million inpatient hospital records and found a significant statistical association between marijuana use, stroke, and heart failure. Compared to non-marijuana users, marijuana users showed:
    • 26% increase in risk of stroke
    • 10% increase in risk of developing heart failure
The Lungs
Liver, Kidneys, Pancreas
  • We found no studies with data on long-term negative effects of marijuana use on these organs.


The following information describes the effects of non-prescription amphetamine abuse, specifically abuse of methamphetamine, on the major organs of the body. Ongoing research examines the effects of prescription amphetamines commonly used to treat ADD/ADHD and other behavioral disorders. The results of those studies are not included here. Methamphetamine abuse also causes a host of emotional and behavioral abnormalities we won’t address here. For a general discussion of the dangers of amphetamine/methamphetamine abuse, please read this article from Psychology Today.

We’ll now look at the specific physical effects of amphetamine abuse on the major organs.

The Brain
The Heart

Evidence shows chronic amphetamine abuse can cause:

  • Arrhythmias: Irregular heartbeat
  • Coronary vasospasm: Sudden constriction of coronary (heart) arteries that stop blood flow
  • Myocardial ischemia: Reduced blood flow to the heart
  • Myocardial infarction: Heart attack
  • Cardiomyopathy: Heart disease, which can lead to heart failure

In addition, heart attack and stroke can be acute, rather than the result of chronic use. In high enough doses, one instance of amphetamine use can result in a life-threatening cardiac episode.

The Liver

Evidence shows chronic amphetamine abuse can cause:

  • Liver damage and liver failure. Both can lead to death.
  • Hepatitis, i.e. swelling of the liver. Some forms of hepatitis, if untreated, can lead to severe liver damage, liver cancer, and death.
The Kidneys

Evidence shows chronic amphetamine abuse can cause:

  • Acute Kidney Injury (AKI): a rapid and dangerous decline in kidney function
  • Rhabdomyolysis: breakdown of muscle tissue, causing toxins to overwhelm the kidneys, which may partially or totally shut down. If not addressed with appropriate medical intervention, kidney failure can lead to death.
  • Hyperthermia dependent liver damage: injury to the liver caused by amphetamine-induced increase in body temperature

Methamphetamine abuse can also cause an increased risk of developing oral caries – a.k.a. cavities. Colloquially, oral problems from amphetamine use is known as meth mouth. Chronic methamphetamine abusers are four times more likely than non-abusers to develop cavities. Also, they’re twice as likely to have two or more missing or decayed teeth.


Opioid abuse affects every system in the body. Chronic exposure to both prescription and illicit opiates impairs cognitive function, inhibits immunity, and damages all the major organs.

The Brain
  • Prolonged use of opioids causes deterioration of white matter in the brain. It also causes changes in the structure and function of the amygdala, nucleus accumbens, and the anterior cingulate.
    • Changes in these brain structures profoundly affect thought and behavior. They’re key players in memory, survival instinct, cognition, risk/reward analysis, decision making, and impulse control.
  • Prolonged opioid abuse decreases the expression of a set of cell surface receptors that evolved to interact with endogenous opioids (opioids produced naturally in the brain). Decreased expression of these receptors results in tolerance, which means the user needs more of the drug to achieve the same effect.
    • Changes in cell surface receptors in the brain cause changes in existing neurotransmitter systems, which affect the ability of an individual to experience pleasure from food, sex, and other natural sources.
The Heart
  • Opiates are central nervous system depressants. Therefore, in high doses, they can cause the heart to slow down to a point at which blood no longer circulates. This can lead to death.
  • Chronic opioid use – especially intravenous heroin use – can lead to infections in cardiac tissue.
The Liver
  • The primary risk to the liver associated with opioid abuse comes from prescription opioids that include acetaminophen.  When the liver is forced to process too much acetaminophen,  permanent liver damage or complete liver failure can occur.
The Kidneys
  • Chronic opioid abuse can lead to Acute Kidney Injury (AKI) and Chronic Kidney Disease (CKD). Both conditions require medical intervention to prevent further complications.
  • Opioid overdose may lead to coma, which, in turn, can lead rhabdomyolysis. Rhabdomyolysis can lead to kidney failure, which, if untreated, can be fatal.
  • Chronic heroin use can cause a type of permanent kidney damage known as heroin associated nephropathy.
The Immune System, the Digestive System, and the Endocrine System
  • Decades of clinical studies show chronic exposure to opioids suppresses optimal immune function. This puts individuals who abuse opioids at risk of developing typical infectious diseases at a higher rate than individuals who do not abuse opioids.
  • Opioids can cause nausea, bloating, constipation, vomiting, and a painful gastrointestinal condition known as narcotic bowel syndrome.
  • Opioids are known to suppress the HPG (hypothalamus-pituitary-gonadal axis) and the HPA (hypothalamus-pituitary-adrenal axis). These systems control the release of crucial hormones into the bloodstream. Disruption of the HPA and HGP can lead to decreased libido, decreased muscle mass, fatigue, depression, anxiety, impotence in men, and menstrual issues in women.

What to Do With This Information

That’s a lot to digest.

If you use this article as a springboard for discussion with your teen, as we advise, you might want to take it one drug at a time. A teen might mentally check out after the first few facts. However, since the information in this article is directly relevant to their lives, they need to hear all of it. Drugs are easy to acquire, and the data show that teenagers are likely to take them. Offering scientific data can help them understand the very real dangers that accompany drug use. It might not prevent them from experimenting, but it may prevent experimentation from becoming habit, habit from becoming chronic use, and chronic use becoming a substance use disorder that changes the course of their lives.

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