Clinical Pearls & Morning Reports
Published December 13, 2023
In the United States, an estimated 52.4 million persons 12 years of age or older used cannabis in 2021, representing 18.7% of the community-dwelling population in that age group, and 16.2 million persons met the diagnostic criteria for cannabis use disorder, which has as its core feature the use of cannabis despite adverse consequences. Read the NEJM Review Article here.
Q: What are the adverse outcomes that have been linked to cannabis use?
A: Cannabis use is most strongly associated with an increased risk of motor vehicle crashes, suicidality, and cardiovascular and pulmonary disease. Cannabis use was associated with an estimated 10% of drug-related emergency department visits in the United States in 2021. Whether cannabis use is significantly associated with increased all-cause mortality remains unclear.
Q: Should primary care physicians screen patients for cannabis use disorder?
A: The U.S. Preventive Services Task Force recommends screening all adolescents and adults in primary care settings for substance use disorders, including cannabis use disorder, as long as “services for accurate diagnosis, effective treatment, and appropriate care can be offered or referred.” Screening is best done with a validated, brief instrument, to be completed by the patient, either used as a stand-alone questionnaire or embedded in a larger health questionnaire.
A: The major risk factors for development of cannabis use disorder are the frequency and duration of cannabis use. The amount and the potency of the cannabis that is used are also likely risk factors, but they have not been well studied because of the difficulty in reliably quantifying the amount and the potency of the 9-tetrahydrocannabinol (THC - the primary psychoactive compound in cannabis) content of products that are illicit at the federal level and loosely regulated at the state level. The potency of cannabis has doubled over the past 2 decades, according to analyses of samples seized by U.S. law enforcement, which may contribute to the increased risk of cannabis use disorder and cannabis-induced psychosis. Cannabis use disorder often occurs alongside psychiatric conditions, including other substance use disorders. About two thirds of persons given a diagnosis of cannabis use disorder have at least one other current substance use disorder, most commonly alcohol or tobacco. Almost half the persons with a diagnosis of cannabis use disorder have a current psychiatric disorder that is not a substance use disorder — most commonly major depression, post-traumatic stress disorder, or generalized anxiety disorder.
A: Medication plays little or no role in the treatment of cannabis use disorder. Psychosocial treatments have significant short-term (2 to 4 months) efficacy in helping patients reduce or stop their cannabis use. Few studies of longer-term treatment outcomes have been conducted, but cannabis abstinence is usually sustained over the long term by less than 50% of patients. The most robust evidence of efficacy is for cognitive behavioral therapy (CBT) and motivational enhancement therapy (MET). CBT emphasizes identification and management of the patient’s thoughts, behaviors, and external triggers that promote cannabis use. MET is a directive, patient-centered form of psychotherapy that aims to enhance the patient’s motivation to reduce or stop cannabis use by using personalized feedback and education regarding the patient’s maladaptive patterns of cannabis use. Patients who do not have an adequate response to CBT or MET may benefit from combining the two or from augmentation with contingency management. Contingency management uses behavioral reinforcement techniques to encourage specific beneficial behaviors. Typically, patients are rewarded with a voucher (redeemable for a low-value prize) each time they attend a treatment session or provide a urine sample that is negative for cannabis.