Experts Warn of Marijuana’s Long-Term Damage to Brain and Developing Fetuses Amid Push for Reclassification

The Biden administration’s recent proposal to reclassify marijuana as a Schedule III drug, equating it with substances like anabolic steroids and Tylenol with codeine, has ignited a contentious debate. While supporters assert that this reclassification would offer tax advantages and invigorate the cannabis industry, health experts caution about the severe negative impacts of marijuana use.

Rising Marijuana Use and Legalization Trends

A 2022 survey sponsored by the National Institutes of Health revealed that 28.8% of Americans aged 19 to 30 had used marijuana in the previous month, a rate more than three times higher than cigarette use in the same age group. Among adults aged 35 to 50, 17.3% reported using marijuana, compared to 12.2% who smoked cigarettes. Although marijuana remains federally illegal, it is now authorized for recreational use in 24 states and for medical purposes in 14 additional states.

Health Risks and Addiction

Bertha Madras, a psychobiology professor at Harvard Medical School and a leading authority on marijuana, strongly opposes the reclassification. In a recent opinion piece for the Wall Street Journal, she stated, “It’s a political decision, not a scientific one. And it’s a tragic one.” Madras, who has spent 60 years studying psychoactive drugs, underscores the high addiction potential of marijuana, especially among young people. About 30% of cannabis users develop some degree of use disorder, compared to 13.5% of alcohol users. Madras emphasizes that marijuana use is primarily aimed at intoxication and notes that academic performance and college completion rates are significantly lower among marijuana users than alcohol drinkers.

Cognitive Impairment and Driving Risks

Marijuana use significantly impairs cognitive function and driving safety. Unlike alcohol, there are no established medical “cutoff points” to determine when it’s safe to drive after using marijuana. States with legal marijuana have reported increased car accidents. “Marijuana just sits there and promotes brain adaptation,” explains Madras, noting that the substance remains in the brain much longer than alcohol.

High-Potency Marijuana and Mental Health

The potency of today’s cannabis is far greater than it was 30 years ago, with significantly higher levels of THC, the main psychoactive component. This increased potency elevates the risks of marijuana use, including anxiety, depression, impaired memory, and cannabis hyperemesis syndrome—a condition characterized by severe vomiting due to prolonged use. Madras points to evidence suggesting that cannabis can induce schizophrenia. A study of 6.9 million Danes indicated that up to 30% of schizophrenia diagnoses in young men could have been prevented if they had not become dependent on marijuana. She highlights that users of other potent recreational drugs develop chronic psychosis at much lower rates compared to marijuana users.

Impact on Pregnant Women and Children

The growing use of marijuana among pregnant women is another major concern. Marijuana use during pregnancy has been linked to higher rates of preterm births, neonatal intensive care unit admissions, lower birth weights, and smaller head circumferences. THC, the active ingredient in cannabis, crosses the placenta and affects fetal brain development. Adolescents exposed to THC in utero exhibit increased aggressive behavior, cognitive dysfunction, and symptoms of ADHD and OCD.

Lack of Medicinal Benefits

Despite widespread claims about marijuana’s medicinal benefits, Madras has found strong evidence supporting its use only for neuropathic pain. For other types of pain and conditions, high-quality trials do not provide robust evidence of benefits. She compares the current promotion of marijuana to the marketing of opioids, where benefits are exaggerated and risks minimized.

The Call for Rigorous Research

Madras disputes the claim that cannabis cannot be adequately studied while classified as a Schedule I substance. She has successfully researched THC despite the additional regulatory paperwork. Madras calls on wealthy donors and advocates to fund rigorous clinical trials instead of ballot initiatives.

Conclusion

Reclassifying marijuana would not legalize its recreational use under federal law but would enable businesses to deduct expenses and culturally signal that marijuana use is normal. Madras warns that this sets a dangerous precedent and undermines efforts to prevent addiction. “This is not a war on drugs,” she asserts. “It’s a defense of the human brain at every possible age from in utero to old age.”

The debate over marijuana reclassification highlights the need to carefully weigh potential benefits against the significant health risks outlined by experts like Madras.