Health Risks of Marijuana Use

Dr. Hopewell is also a retired Major in the United States Army, serving active duty both in the U.S. as well as abroad during the Vietnam Era, Cold War, and Operation Iraqi Freedom serving 27 years total active military service. He was the first medical Psychologist Army Officer to enter active duty with a state license as a Prescribing Psychologist and first Army Officer Prescribing Psychologist to serve and to practice in a Combat Theater. Dr. Hopewell received a Bronze Star Medal for meritorious service,  Operation Iraqi  Freedom, and a Meritorious Service Medal for Valor and Courage Above the Call of Duty during Ft. Hood Jihadist Terrorist attack, among other prestigious awards.

Students at the University of North Texas in the early 1970s were often shown the 1936 film Reefer Madness. This movie aimed to raise awareness about substance use but was routinely criticized as being hysterical propaganda and misleading. Many made fun of the film and subsequently discounted any dangers from marijuana use. Also, during the “hippie revolution” of the 1960s, the mantra of criticism of alcohol use was incessant with the refrain being that marijuana was essentially a harmless agent, especially when compared to the evils of the older generation using alcohol. These types of views have become mainstream in society, with the resultant relaxation of essentially any laws prohibiting marijuana use and the widespread endorsement and commercialization of this drug.

However, the truth is that “reefer madness” is closer to the reality of the hazards of marijuana use than most people would like to acknowledge. As marijuana use, with its active ingredient THC (delta-9-tetrahydrocannabinol or Δ-9-tetrahydrocannabinol (Δ-9-THC), has become more widely acceptable, research into its harmful side effects has also become more thorough. All such research now increasingly points to the dangers of even casual marijuana use, especially among teenagers who are still developing their nervous systems. Most risks can be summarized under the headings of 1) danger of addiction, 2) cognitive effects, 3) psychiatric effects, 4) medical/ physical effects, and 5) driving risks.

Danger of Addiction 

Dangers of addiction are often downplayed for marijuana use, but the truth is that marijuana is usually the primary “gateway drug” to later addiction of other substances. The Substance Abuse and Mental Health Services Administration (SAMHSA) estimates that current strains of marijuana are about three times stronger than they were 25 years ago, and that at least three in every ten users will become addicted.

Cognitive Disorders

SAMHSA has also documented that using marijuana can affect memory, learning, concentration, and attention. Other effects include difficulty with thinking and problem solving. Marijuana also affects brain development. Use by adolescents has been linked to a decline in IQ scores — up to 8 points! Worse yet, IQ reduction does not seem to recover even with cessation of marijuana use. Compared with teens who don’t use, students who use marijuana are more likely not to finish high school or get a college degree.

Psychiatric Risks 

Marijuana use has additionally been linked to an increased chance for mental illness, especially among teens. In addition to addiction, marijuana use is linked with a higher risk for schizophrenia, depression, and anxiety. Psychotic breaks can affect the mind and make it hard for a person to understand what’s real and what isn’t. SAMHSA has found that some people have a gene that may increase the chance of long-lasting psychotic disorders, such as schizophrenia, when they repeatedly use marijuana.

Medical and Physical Risks 

Marijuana users are nearly 25% more likely than non-users to go to the Emergency Room or be hospitalized. Marijuana-related hospitalizations in Colorado have increased 148%. Emergency department visits and admissions related to marijuana in California are also up 89% following legalization. A 2022 retrospective cohort study in Colorado found marijuana to be associated with a two-fold increase in marijuana-related hospitalizations of pregnant women. A 2023 study found that prenatal exposure to THC has long-term effects and inhibits brain and neural development in babies. Using marijuana when pregnant has been linked to lower birth weight, preterm birth and stillbirth, and the increased risk of brain and behavioral problems.

Driving Risks 

People who drive under the influence of marijuana can experience dangerous effects: slower reactions, lane weaving, decreased coordination, and difficulty reacting to signals and sounds on the road. Colorado, for example, has seen a dramatic increase in motor vehicle accidents and tickets since legalizing marijuana. Research shows that marijuana affects safe driving skills, like judgment, coordination, and reaction time. Marijuana makes it hard to judge distances and react to signals and sounds on the road. As with any psychoactive drug, impaired driving can cause deadly vehicle crashes. One in every four roads deaths in Colorado have now been linked to marijuana use. It has also been estimated that if marijuana were legalized nationwide, the U.S. would suffer an additional 6,800 excess fatal crashes every year.

“Reefer madness” – maybe not so wrong after all!