Impacts of Chronic Marijuana Use

In June 2018, medical marijuana was legalized in Oklahoma. Now, there are more than 340,000 active patient licenses throughout the state. Marijuana can be used for a variety of medical conditions, including cancer, appetite loss, epilepsy, mental illness, muscle spasms, chronic pain and more.

While there are many benefits of medical marijuana, it’s important to understand the long-term effects of chronic marijuana use. Because marijuana, also known as cannabis, has only recently been legalized in many parts of the country, long-term studies are lacking, which can make it difficult to weigh the benefits and risks.

Jedidiah Perdue, M.D., medical director at Arcadia Trails INTEGRIS Center for Addiction Recovery, offers his expertise and shares what you should know about how marijuana impacts the body and mind over time.

Immediate effects of cannabis

The immediate effects of cannabis may vary based on the amount, strain and potency. However, in general, marijuana can have the following effects for one to three hours when inhaled and several hours when ingested:

• Increased relaxation or pleasure
• Heightened senses
• Increased appetite
• Impairments in short-term memory, attention, reaction time and motor coordination

The immediate effects of cannabis are often the reason for its use. These effects can help people who experience anxiety, loss of appetite or chronic pain. However, when taken in higher doses or potencies, people can experience the following negative effects:

• Increased anxiety
• Perceptual disturbances
• Rapid heart rate
• Dizziness upon standing
• Red eyes

Long-term effects of cannabis

Long-term effects occur over time due to heavy or chronic use.

“Generally speaking, heavy use refers to daily or near-daily use of cannabis at an amount sufficient to lead to intoxication,” Dr. Perdue says. “When a person continues to use cannabis on a regular basis for months or years, we describe that as chronic or prolonged.”

Chronic use of cannabis can result in the following long-term effects:

• Mood changes
• Anxiety
• Low motivation
• Impaired verbal memory
• Cannabis tolerance

With prolonged use, the brain makes adaptations that lead to the development of tolerance, where your body requires more cannabis to achieve the same desired effect. Consequently, it’s possible to experience symptoms of withdrawal upon stopping. Withdrawal typically begins within two days after stopping and includes problems with sleep, decreased appetite, anxiety, restlessness and irritability. Cannabis withdrawal is uncomfortable but not medically severe. Symptoms can last seven to 14 days and resolve on their own.

“One particular condition to be aware of is cannabinoid hyperemesis syndrome (CHS),” Dr. Perdue warns. “This highly unpleasant illness involves cyclical vomiting triggered by frequent use of cannabis. Nausea is pronounced and may abate temporarily with a hot shower. Fortunately, this syndrome improves upon stopping cannabis.”

Permanent effects of chronic cannabis use

Most long-term effects of chronic cannabis use are reversible and tend to improve within a few weeks after stopping all cannabis use. However, for some individuals, especially chronic users who started using cannabis in adolescence, changes can be long-lasting or even permanent.

“Chronic use of cannabis has been associated with deficits in verbal memory, which may persist even after stopping,” Dr. Perdue says. “There is also a risk of psychiatric disorders, including schizophrenia, most pronounced among adolescents with genetic risk factors and those using highly-potent forms of cannabis.”

Cannabis use disorder is a diagnosis recently introduced by the Diagnostic and Statistical Manual of Mental Disorders and is characterized by the presence of at least two of the following symptoms within a 12-month period.

• Taking more cannabis than intended
• Difficulty controlling cannabis use
• Spending a lot of time on cannabis use
• Craving cannabis
• Problems at work, school and home as a result of cannabis use
• Continuing to use cannabis despite social or relationship problems
• Giving up or reducing other activities in favor of cannabis
• Taking cannabis in high-risk situations
• Continuing to use cannabis despite physical or psychological problems
• Tolerance to cannabis
• Withdrawal when discontinuing cannabis

Treatments for cannabis use disorder

Although there are no medications approved by the Food and Drug Administrations (FDA) for cannabis use disorder, some medications may be useful in addressing symptoms of withdrawal and anxiety or depressive symptoms resulting from chronic use.

“At Arcadia Trails, we find that a multidimensional approach blending therapy, groups and wellness works quite well in helping a person recover,” Dr. Perdue says. “There is evidence for psychosocial interventions such as cognitive behavioral therapy, motivational enhancement therapy and contingency management in treating cannabis use disorder. Peer recovery groups such as AA are effective at supporting recovery, as well as residential treatment for those with more severe addiction or for whom other interventions are unsuccessful.”

Things to consider before using medical marijuana

It’s important to consider your risk factors when choosing to use cannabis for medical purposes. Approximately 9 percent of those who use cannabis show signs of dependence.

“Individuals choosing to utilize cannabis should understand there’s a potential for addiction,” Dr. Perdue says. “I try to understand an individual’s risk in order to have an open conversation about the balance of risks and expected benefits. Adolescents, individuals with a personal or strong family history of serious mental illness or addiction and the elderly are at highest risk for adverse effects.”

Dosage and method of use are also important considerations. For example, smoking or vaping cannabis isn't recommended, as it can lead to similar health complications as smoking cigarettes.

“Patients should be careful to choose low-potency products that have a low tetrahydrocannabinol (THC) to cannabidiol (CBD) ratio, as CBD may offset some of the neurotoxic properties of THC,” Dr. Perdue recommends. “Many find indica strains to be more calming than sativa, which may heighten anxiety. Patients should be careful about dose: 5 mg is often sufficient, but edibles are often sold at 10-20 mg increments.”

If you have questions about whether medical marijuana is right for you, contact an INTEGRIS Health physician today to discuss potential risks. For more healthy living tips, check out our On Your Health blog.