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An Introduction to Substance Use Disorders for Dental Professionals

Course Number: 545


Cannabis (marijuana, hashish, and hash oil) is also known as weed, pot, reefer, joint, Mary Jane, ganja, grass, sinsemilla, and dope. Additionally, blunts are cigars emptied of some tobacco and refilled with marijuana. Marijuana is still the most commonly used illegal drug in the United States, although it has become legal in many states. In 2022, there were 42.3 million current users aged 12 and older, up from 30 million in 2019 and 19.8 million users in 2013.60,61 Marijuana laws are changing and may result in an increase in use. As of January 2024, 24 states in the United States have legalized recreational marijuana either by ballot measure or other legislative action.6,47 Thirty-eight states allow for the use of medical marijuana.

Marijuana increases dopamine, which creates the euphoria or “high” associated with its use. A user may feel the urge to smoke marijuana again and again to re-create that experience. Repeated use could lead to addiction – a disease where people continue to do something, even when they are aware of the severe negative consequences at the personal, social, academic, and professional levels.

Cannabis may be smoked as a cigarette, vaped in a pipe, as well as added to foods. A common way to use marijuana is through a “bong” in which the smoke is drawn through a layer of water that cools the smoke and removes some of the tar and irritants.

When marijuana is smoked, tetrahydrocannabinol (THC) rapidly passes from the lungs into the bloodstream, which carries the chemical to the brain and other organs throughout the body.

Contrary to common belief, marijuana is addictive. Research suggests that between 9-20% of those who use marijuana may develop some degree of marijuana use disorder. People who begin using marijuana before age 18 are 4-7 times more likely than adults to develop a marijuana use disorder.29,76 People who use marijuana may also experience a withdrawal syndrome when they stop using the drug. This withdrawal is similar to what happens to tobacco smokers when they quit – people report being irritable, having sleep problems, and losing weight. Symptoms can last for several days to a few weeks after drug use is stopped. Relapse is common during this period, as users also crave the drug to relieve these symptoms.47

Cannabidiol (CBD) is the second most prevalent of the active ingredients of cannabis marijuana. While CBD is an essential component of medical marijuana, it is derived directly from the hemp plant, which is a cousin of the marijuana plant. While CBD is a component of marijuana (one of hundreds), by itself it does not cause a “high.” CBD has been used to reduce seizures, anxiety and chronic pain. CBD exhibits no effects indicative of any abuse or dependence potential.26 There is some evidence that CBD can be used to treat some addictive behaviors, however more research is necessary. 54 Synthetic marijuana (also known as synthetic cannabinoids, K2, or Spice) is part of a group of drugs called new psychoactive substances (NPS). They are unregulated, have become newly available on the market, and are intended to produce the same effect as marijuana. Synthetic marijuana is human-made and contains mind-altering chemicals that are either sprayed on dried, shredded plant material so they can be smoked or sold as liquids to be vaporized and inhaled in e-cigarettes and other devices. These products are also known as herbal or liquid incense. Synthetic marijuana may be contaminated with other illicit drugs including opioids and/or methamphetamine.71