Effects of long-term or heavy use include:
• Addiction (in about 9% of users overall or 2.7 million Americans, 17% of
those who begin use in adolescence, and 25% to 50% of those who are
• Altered brain development including impaired neural connectivity
• Poor educational outcome, with an increased likelihood of dropping out
• Cognitive impairment, with lower IQ among those who were frequent users
• Diminished life satisfaction and achievement (determined on the basis of
subjective and objective measures as compared with such ratings in the
• Symptoms of chronic bronchitis, but a risk of lung cancer has not been
• An association with increased risk of anxiety, depression and chronic psychosis
disorders (including schizophrenia) in persons with a predisposition to such
disorders, but causality has not been established
• Long-lasting changes in brain function that can jeopardize educational,
professional, and social success.
Especially young, developing brains are likely more susceptible to harm from marijuana
than adult brains. In another study reported by the NIDA, researchers followed
people from ages 13 to 38. They found that heavy users of marijuana in their
teens who continued frequent use into adulthood had a significant drop in IQ, even
if they quit. Effects can also be unpredictable when marijuana is used in combination
with other drugs, but it is known that marijuana and alcohol potentiate the
harmful effects of each of the drugs. If a person is committed to trying marijuana,
they should at least wait until they’re older than age 25 when their brains are fully
Many people erroneously think marijuana is not addictive. About 9% of people
who use marijuana become dependent on it. The number increases to about one in
six among those who start using it at a young age, and to 25% to 50% among daily
users. By comparison, cocaine, a schedule 2 substance with supposedly less abuse
potential than a schedule 1 drug like marijuana, causes 17% of those who use it to
become addicted, and 23% of heroin users become addicted. Nicotine’s addiction
potential in tobacco is even worse, affecting an estimated 32% of smokers, many of
whom go on to die from lung cancer, heart disease, and other tobacco-linked causes.
While most people who smoke marijuana do not go on to use other drugs, long-term
studies of high school students show that few young people use other illegal drugs
without first trying marijuana.
People who use marijuana may also experience a withdrawal syndrome when they
stop using the drug. It is similar to what happens to tobacco smokers when they
quit—people report being irritable, having sleep problems, and weight loss—effects
that can last for several days to a few weeks after drug use is stopped.
Currently, no medications exist for treating marijuana addiction. Treatment programs
use behavioral therapies, and a number of programs are designed specifically
to help teenagers who misuse marijuana. In addition to reaching out to talk to a
parent, school guidance counselor, or other trusted adult, there are also anonymous
resources, such as the National Suicide Prevention Lifeline (1-800-273-TALK) and
the Treatment Referral Helpline (1-800-662-HELP). The Treatment Referral Helpline
is provided by the Substance Abuse and Mental Health Services Administration. It refers callers to treatment facilities, support groups, and other local organizations that can provide help for their specific needs. Treatment centers can also be located by going to www.samhsa.gov/treatment.
This blog presents opinions and ideas and is intended to provide helpful general information. I am not engaged in rendering advice or services to the individual reader. The ideas, procedures and suggestions in that are presented are not in any way a substitute for the advice and care of the reader’s own physician or other medical professional based on the reader’s own individual conditions, symptoms or concerns. If the reader needs personal medical, health, dietary, exercise or other assistance or advice the reader should consult a physician and/or other qualified health professionals. The author specifically disclaims all responsibility for any injury, damage or loss that the reader may incur as a direct or indirect consequence of following any directions or suggestions given in this blog or participating in any programs described in this blog or in the book, The Building Blocks of Health––How to Optimize Your Health with a Lifestyle Checklist (available in print or downloaded at Amazon, Apple, Barnes and Noble and elsewhere). Copyright 2021 by J. Joseph Speidel.