Marijuana (Cannabis) Use Disorder

Description

Marijuana or cannabis use disorder is classified into different categories (mild, moderate, or severe) depending on how many symptoms are present. Mild: 2 to 3; moderate: 4 to 5; severe: 6+ (1). The definition is used when use leads to clinically significant impairment or distress, manifested by two or more of the following symptoms within a 12-month period:

• Taken in larger amounts and over a longer period of time than intended
• Persistent desire or unsuccessful efforts to cut down or control amount used
• A great deal of time spent in activities is necessary to obtain, use, or recover from use.
• Presence of craving for the substance
• Recurrent use resulting in failure to fulfill major role obligations at work, school, or home
• Continued use despite having persistent or recurrent social or interpersonal problems due to cannabis use
• Important social, occupational, or recreational activities are given up or reduced.
• Recurrent use in physically hazardous situations
• Use is continued despite knowledge of having a persistent physical or psychological problem caused or exacerbated by cannabis.
• Tolerance defined by using increased amounts of cannabis to achieve the desired effect or intoxication or diminished effect with continued use of the same amount
• Withdrawal

Epidemiology

• The United States is ranked first among 17 European and North American countries by the World Health Organization for prevalence of marijuana use.
• Cannabis is the most widely used illicit psychoactive substance in the United States (2).
• In 2014, an estimated 22 million Americans, 12 years old and older, self-identified as current marijuana users
• 45% of 12th graders have tried marijuana.
• Approximately 30% of students have used marijuana at the time of college entry (3).
• In the United States, 10% of marijuana users become daily users, 20–30% become weekly users.
• Younger users have a higher rate of addiction; 1 in 6 adolescents become addicted with repeated use.
• Marijuana use is increasing in pregnant women. In 2002, 2% reported using in the last month.
• In 2014, 7% of 18- to 25-year-old women reported use.
• In the United States, the legal landscape is changing rapidly. Multiple states have approved recreational marijuana use.
• Even more states have legalized medical marijuana.

Etiology and Pathophysiology

• Currently, there are two well-known therapeutically active cannabinoids in marijuana, delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD).
• THC is responsible for marijuana’s analgesic, anti-emetic, and intoxicating properties.
• Cannabidiol is the nonpsychoactive component responsible for marijuana’s antianxiety, antidepressant, antipsychotic, antispastic, anticonvulsant, and antineoplastic properties.
• In terms of bioavailability, smoking marijuana results in 25–50% absorption of THC, which rapidly passes into the circulation. When ingested, the oral bioavailability of THC is significantly less (only 3–10%).
• Effects of smoked marijuana occur within minutes and last several hours.
• Effects from marijuana consumed in foods or beverages appear after 30 minutes to 1 hour and can last up to 4 hours.
• Cannabinoid receptors (CBRs) are associated with memory, thinking, concentration, sensory/time perception, pleasure, movement, and coordination.
• THC artificially stimulates the CBRs, disrupting the function of endogenous cannabinoids. A marijuana “high” results from overstimulation of these receptors.
• With time, overstimulation alters the function of CBRs, leading to addiction and withdrawal.

Risk Factors

• Age (highest use among those 18 to 25 years)
• Male sex
• Comorbid psychiatric disorders (i.e., bipolar disorder, posttraumatic stress disorder [PTSD])
• Other substance use (i.e., alcohol, cocaine)
• Lower educational achievement (rates of dependence are lowest among college graduates)
• Employment status and income