An epidemic of emotional problems in our adolescent/young adult population has received wide acknowledgment. Important issues contributing to this increase of anxiety, depression and self-harm behaviors includes the influence of psychosocial stressors, social media, bullying, trauma and the lack of school attendance during the COVID-19 pandemic. The possible role of THC has been largely ignored. Clinical studies are often confusing as terms like medical marijuana and cannabis may not distinguish the amount of THC and CBD involved.
Although adolescents do not die from cannabis overdose as they may from opiates, tetrahydrocannabinol (THC) – the euphoric-inducing cannabinoid in cannabis – is toxic to the adolescent brain. Significant brain development occurs in adolescence at puberty with increased synaptogenesis in the prefrontal cortex that controls attention, impulsivity, emotional regulation and recognition of the consequences of one’s actions. This is then followed by significant pruning which continues until age 25 years.
THC interferes with the functioning of the endogenous cannabinoid anandamide, which is a retrograde neurotransmitter that modulates the release of other synaptic chemicals. Thus the developing adolescent brain is vulnerable to the toxic effects of THC marijuana.
We are seeing an increase of adolescent cannabis use, but the most significant negative development is the increase in THC potency. Cannabis plants have been bred specifically to increase the potency so that smoked marijuana leaves may contain 10% to 20% THC. The most alarming development is that the concentration in vaped THC can be as high as 80% to 90%. Although teenagers will often say they are only vaping nicotine, the same vapes are used for high-THC cartridges. In many Georgia high schools, students are vaping THC in bathrooms during the school day, which is very difficult to detect. Delta-8 and Delta-10 are legally available at CBD stores and gas stations. They are less potent and yield a lower-level marijuana high but give the message that it is OK to smoke pot.
THC impairs cognitive functioning including working memory, attention, information processing, judgment and decision making. Some adolescents develop an acute psychosis, which frequently recurs if they smoke again after remission. Follow-up studies have shown that cannabis use increases the risk of the future development of schizophrenia. Regular cannabis use in adolescence also increases the risk of depression, suicide attempts, anxiety and gastrointestinal problems.
It is important to recognize that the use of THC marijuana impairs driving ability. As one professional described it, “if you’re drunk you run the red lights, while if you’re stoned, you stop at the green lights.” Studies have shown that a small amount of alcohol combined with smoking THC marijuana causes increased driving impairment.
In our adolescent substance abuse intensive outpatient program during 2020 and 2021, approximately 40% of the teens reported that cannabis use was their drug of choice. When teenagers progressed from smoking marijuana a few times a week to vaping high concentrated THC 3 to 4 times a week, their school work declined and cannabis use became the focus of their lives. Teenagers with ADHD, anxiety, depression and suicidal ideation often will smoke marijuana in an effort to get some relief, but that often only leads to THC addiction. THC use in these adolescence leads to negative cognitive and motivational effects, which may interfere with their treatment.
THC-marijuana’s effect on the prefrontal cortex often impairs their ability to recognize the negative effects from THC marijuana. Clinicians need to make an effort to decrease or eliminate THC marijuana use in their adolescent patients. Educating adolescents as to the negative effects of THC, as well as how long it stays in the brain (a single joint lasts a week while a chronic smoker will last a month), we ask patients to commit to 30 days without marijuana to see for themselves how different and clearheaded they feel.
Family therapy helps parents set appropriate limits. Attendance at recovery groups supports sobriety. Teens need to recognize that THC marijuana use interferes with psychosocial therapies and may interfere with psychopharmacological treatments of comorbid conditions.
From a psychodynamic perspective, adolescence is a time of learning to develop the ego strategies to deal with anxiety, loss and disappointment. If an adolescent uses THC to cope with these normal developmental challenges, basic ego factors may be stunted and a more narcissistic, less empathic young adult may develop.
Clinicians need to ask every adolescent, especially those with emotional challenges, about the role that cannabis plays in their life and educate them on the negative impact it may have on their brain development. Parents, adolescents, teachers and healthcare providers need to become aware that regular THC use in adolescence is not a benign activity and can have life-changing consequences.
Dr. Jaffe is a Professor Emeritus of Psychiatry, Emory University School of Medicine; Clinical Professor, Morehouse School of Medicine; and Clinical Director, Atlanta Insight Adolescent Substance Abuse Treatment Program.
