Cannabis: Expert Report Details Health Effects -- Good and Bad


The growing acceptance, accessibility, and use of cannabis and its derivatives have raised important public health concerns ; 22 million Americans older than 12 years report current cannabis use ― the majority for recreational purposes. Twenty-eight states and Washington, DC, have legalized marijuana for medical use, and eight states and the District of Columbia allow recreational use.

The movement in Canada to legalize both medicinal and recreational use of cannabis was in part an attempt to eliminate the illegal trafficking of the drug. With criminal penalties in place, the police, courts and prisons at great cost were unsuccessful in suppressing the market for the drug. Other arguments for governments gaining the revenue that criminal organizations received were persuasive.

The problem, of course, is that cannabis-using citizens are drugged, dangerous drivers and are compromised in their learning, social interactions and employability. We already have a drugged society with at least half the population under the influence of mind altering drugs. Another group of psychotropic drugs will get lost in the great festival of brain dysfunction.

According to a 2017 report on the benefits and harms of cannabis from the National Academies of Sciences, Engineering, and Medicine (NAS): their evidence suggests cannabis use is associated with the development of psychoses and schizophrenia, but may have benefits, including alleviating chronic pain and chemotherapy-induced nausea.

Cannabis use before the age of 25 years may impair brain growth and learning. The committee found moderate evidence of increased mania symptoms and hypomania in patients with bipolar disorder who use cannabis regularly, and there was evidence of an increase in the incidence of suicidal ideation and suicide attempts with heavy use. It also reported substantial evidence linking greater frequency of cannabis use and an increased likelihood of developing problem cannabis use, and that initiating cannabis use at a younger age increases the likelihood of problem use. Cannabis may pose risks, including a worsening of respiratory symptoms and more frequent bronchitis with long-term smoking, an increase in motor vehicle accidents, and low birth weight in offspring of maternal smokers. The committee also found an increased risk for cannabis overdose in children in states where the substance is legal. Cannabis may cause respiratory symptoms and more frequent bronchitis, an increase in motor vehicle accidents, and low birth weight in offspring of maternal smokers. The committee also found an increased risk for cannabis overdose in children in states where the substance is legal. (Alicia Ault Medscape January 13, ;2017 )

Researchers at the National Institute on Drug Abuse (NIDA) are sounding the alarm over a possible increase in unknown cognitive and behavioral harms that widespread cannabis use may unmask. They stated: "Science has shown us that marijuana is not a benign drug. The morbidity and mortality from legal drugs is much greater than that for illegal drugs, not because the drugs are more dangerous but because their legal status makes them more accessible and a larger percentage of the population is exposed to them on a regular basis. The current normalization movement presses on with complete disregard for the evidence of marijuana's negative health consequences, and this bias is likely to erode our prevention efforts by decreasing the perception of harm and increasing use among young people, which is the population most vulnerable to the deleterious effects of regular marijuana use."
A clinical review conducted by NIDA director Nora Volkow, MD, points out that as legalization of the drug for recreational and medical use spreads, vulnerable populations, especially adolescents, are exposed to toxic effects of the drug. Dr Volkow explained that young brains are engaged in a protracted period of "brain programming," in which everything an adolescent does or is exposed to can affect the final architecture and network connectivity of the brain. Drugs are powerful disruptors of brain programming because they can directly interfere with the process of neural pruning and interregional brain connectivity. In the short term this interference can negatively affect academic performance. Long-term use can impair behavioral adaptability, mental health, and life trajectories. Emerging evidence suggests that adolescents may be particularly vulnerable to the adverse effects of cannabis use. Several studies, for example, have shown that individuals who use cannabis at an earlier age have greater neuropsychological impairment and that persistent use of cannabis from adolescence was associated with neuropsychological decline from the age of 13 to 38 years. Cannabis use may cause an 'amotivational' state.

(JAMA Psychiatry. 2016;73(3):292-297.

  • You can view the Brain Mind Center at Alpha Online. Understanding the human brain is essential to become a well-informed, modern citizen. Stephen Gislason MD, the author of the Human Brain, is a physician-writer who is good at making complex subjects more understandable. This is a book with important ideas, so be prepared to read and then keep the book as reference.