Marijuana (THC) Effects on Youth

Effects of TCH on the body
Resources compiled 2022, March 22

How Teen Marijuana use may alter the shape of the Brain
Inverse Science, 2021, June 16

New research finds “cannabis is indeed having some sort of an effect on this neuro-maturation process.”

SINCE THE SIZZLING FRIED EGG in the iconic 1987 Partnership for a Drug-Free America ad, we’ve been asked to think about what a “brain on drugs” looks like. Now, we have a slightly better idea, thanks to a study that used MRI scans of adolescent brains at 14 and again at 18 to paint a picture of one plausible effect of marijuana.

The authors write that their study is the “largest longitudinal neuroimaging study of cannabis use to date” and is particularly pertinent because of what we know about adolescent cannabis use: Most people trying marijuana for the first time (78 percent) are between the ages of 12 and 20.

The findings, he says, “might suggest that cannabis is indeed having some sort of an effect on this neuro-maturation process.”..

Is marijuana addictive for teens?
Resources compiled 2020, July 10
Christine L. Miller, Ph.D.

Yes, 17% of those who began their use in adolescence become addicted, and up to about 50% of those who become daily users end up with addiction:….

How can marijuana be addictive and a gateway drug at the same time?
Resources compiled 2020, July 10
Christine L. Miller, Ph.D.

This can happen because the pathways to addiction with different drugs share common features. When marijuana can no longer excite the common pathway as the drug’s receptors become desensitized, the user switches to a new drug. The addiction to marijuana is no longer satisfying. Research has confirmed that marijuana acts as a gateway drug for many users…

What are some of the ways in which marijuana influences adolescent brain development? Resources compiled 2020, July 10
Christine L. Miller, Ph.D.

The best studies are those that follow the same individuals over time (longitudinal), so they know
the baseline starting point for each person. For microstructural effects on white matter in the brain…

What are some of the psychological symptoms that adolescents might try to treat with marijuana, and does it help (e.g. anxiety, depression, ADHD)? Resources compiled 2020, July 1
Christine L. Miller, Ph.D.

The ability of a drug to transiently exert an effect that causes a person to essentially forget about
negative symptoms they are experiencing is important to distinguish from the drug’s long-lasting impact. As a case in point, it is commonly thought that using marijuana reduces anxiety by making you more relaxed. While that can be a short-term effect, the long-term impact can be quite the opposite, anxiety or outright panic becomes worse, almost uniformly during intervals between uses (withdrawal effects)…

Is it true that marijuana triggers transient psychotic episodes?
Resources compiled 2020, July 10
Christine L. Miller, Ph.D.

Yes. Even with the low strength pot common in the last century, 15% of users reported psychotic
episodes. But the proof would have to await studies in the clinic, where it was found that administration of a moderate dose of pure THC would elicit transient psychotic symptoms in study subjects…

Is there also a link to chronic psychosis (schizophrenia) in adolescent use?
Resources compiled 2020, July 10
Christine L. Miller, Ph.D.

Yes, and not just in adolescents. For a long while, the psychiatric community was unsure of the causal basis for the connection, because studying cause and effect is a complicated endeavor. It was important to find out if there was a greater effect at higher dose, which would indicate causality, and such a relationship was confirmed…

How does marijuana compare to other drugs that are associated with psychosis (LSD, cocaine, amphetamine, methamphetamine, PCP)? Resources compiled 2020, July 10
Christine L. Miller, Ph.D.

Marijuana is more likely to lead to chronic psychosis than any other drug studied. About half of those who experience a marijuana-induced psychotic break will eventually develop a schizophrenia spectrum disorder…

Does marijuana use lead to suicidal tendencies in some adolescents?
Resources compiled 2020, July 10

Yes. Two independent studies came up with a very similar elevation in risk (nearly 7-fold). Part of the risk for suicide may be exerted through the mental disorders that marijuana triggers (as
referenced previously), particularly psychotic disorders and depression. However, there is also evidence that marijuana’s effect can be more immediate from a recent study illustrating the likelihood of suicidal thoughts increased on the days when an adolescent uses marijuana. In Colorado, the THC positive toxicology screens in youth aged 15-19 have consistently increased
over the past several years (while such data was being collected by the Colorado Department of
Health), such that it became the leading drug found in suicide victims of that age range (32% were positive by 2017, about 1.5-fold higher than the average monthly use rate for that age group in

Does having schizophrenia in your genetics mean that you would have manifested the disorder anyway?
Resources compiled 2020, July 10
Christine L. Miller, Ph.D.

No one is predestined to develop schizophrenia based on their genetics. Even if you have an
identical twin who develops schizophrenia, only about half the time will the other twin develop
schizophrenia as well. Environmental factors, like marijuana, can make the difference between
leading a normal life and not….

Is there an age where it is MORE risky to develop mental illness, such as 13 or 15?
Resources compiled 2020, July 10
Christine L. Miller, Ph.D.

In the case of bipolar disorder, an early age of onset is more commonly seen in those with a family history of the disease and, those early onset cases have been reported to be more severe than adult onset cases. However, for schizophrenia, original findings of a worse prognosis when the diagnosis occurs as
early as thirteen years of age have now been challenged by a much larger and more recent study, showing that early onset schizophrenia does not carry a worse prognosis. For drug-induced mental illness, while there is some data showing use of marijuana at those young
ages is more likely to lead to chronic mental illness because the brain is still developing, this does not mean it is safe to begin use after the teenage years. A recent study in Europe demonstrated that frequency of use, no matter what the age when use began, was the most significant risk factor for a psychotic break. Irrespective of the age when a marijuana-induced psychotic break occurs, ceasing use is crucial to
improving the odds of recovery (about 50% can recover)…

What would you say to parents who say that it’s “just marijuana,” or “kids will be kids,” or “at least they’re not doing hard drugs.”?
2020, July 10

I would say that marijuana containing THC is one of the most dangerous drugs for mental health out there, a true wolf in sheep’s clothing. Even if it does not lead to the use of other drugs, it is bad
enough all by itself..

Association of High-Potency Cannabis Use With Mental Health and Substance Use in Adolescence
Jama Psychiatry, 2020, May 27

Risks for cannabis use problems and anxiety disorders are higher among those reporting use of high-potency cannabis; provision of public health messaging regarding the importance of reducing both frequency of cannabis use and the potency of the drug, as well as limiting the availability of high-potency cannabis, may be effective for reducing these risks….

Associations of Parental Marijuana Use With Offspring Marijuana, Tobacco, and Alcohol Use and Opioid Misuse  
National Center for Biotechnology Information 2019, November 22

In this cross-sectional study including 24 900 father-offspring or mother-offspring dyads, parental marijuana use was associated with increased risk of marijuana and tobacco use and opioid misuse by both adolescent and young adult offspring and of alcohol use by adolescent offspring. Meaning: Screening household members for substance use and counseling parents on risks posed by current and past marijuana use may be helpful in the effort to prevent a cycle of multigenerational substance use…

What is the difference between a habit and an addiction?
The National Institutes of Health 2015, October 15

A sign that a habit has morphed into an addiction is to see continued usage despite the occurrence
of life-altering negative consequences. To quote Dr. George Koob, head of the National Institute on
Alcohol Abuse and Alcoholism “A healthy brain rewards healthy behaviors—like exercising, eating,
or bonding with loved ones. It does this by switching on brain circuits that make you feel wonderful, which then motivates you to repeat those behaviors……..But when you’re becoming addicted to a substance, that normal hardwiring of helpful brain processes can begin to work against you. Drugs or alcohol can hijack the pleasure/reward circuits in your brain and hook you into wanting more and more. Addiction can also send your emotional danger-sensing circuits into overdrive, making you feel anxious and stressed when you’re not using the drugs or alcohol. At this stage, people often use drugs or alcohol to keep from feeling bad rather than for their pleasurable effects.”..