Lost in the various public policy arguments fueling cannabis decriminalization and legalization laws across the United States is the fact that a percentage of individuals who use cannabis will experience negative effects, ranging from bothersome to the catastrophic. These difficulties arise from a sharply decreasing perception of risk, easy availability of the drug, and increased potency of [DELTA]-9-tetrahydrocannabinol (THC) preparations. The arithmetic of cannabis remains immutable: Best estimates are that about 9% of individuals who use cannabis will become dependent on the substance at some point in their life, (1) and if the number of those who use cannabis goes up, the total number of those experiencing problems with the substance will rise also. Clinicians must learn to manage cannabis-related problems in this growing population.
The acute and chronic problems cannabis-dependent individuals face are serious, disheartening, and deserving of treatment. National Survey on Drug Use and Health (NSDUH) data on 505,796 Americans (2) show that between 2008 and 2016 individuals aged 12 to 17, who met criteria for a cannabis use disorder (CUD), were 25% more common in states that had enacted Recreational marijuana laws (RMLs) as opposed to those who did not. In addition, the THC content of the various preparations of cannabis has risen over the past 10 years. Studies show that the mean THC concentration in smokable marijuana increased from 8.9% in 2008 to 17.1% in 2017, (3) and half of those who frequently use marijuana ingest concentrates of at least 80% THC. (4) In 2014, THC concentrate in Colorado had an average THC percentage of 56.6%, while by 2017 the average was 68.6%, with some retail stores cheerfully advertising a 95% THC rate in their products. (5)
Cannabis-related problems, like lack of motivation, usually become apparent after many years of use. Given cannabis' pharmacological designation as a sedative-hypnotic substance, it is hardly surprising that common complaints on presentation to treatment include acute intoxication with high-potency edible THC preparations (6); psychiatric phenomena such as depression, anxiety, and psychosis (7); and cannabinoid hyperemesis syndrome (CHS). (8)
Clinicians should at least consider their patients' cannabis use as a precipitating or exacerbating factor in any psychiatric or medical syndrome. Also, although the DSM-5 (9) contains a useful list of cannabis-related signs and symptoms, many individuals with cannabis-related problems do not meet the full criteria for CUD. For instance, while the casual cannabis smoker may present with a depressive picture but meet no other criteria for CUD, cessation of cannabis use may be necessary to achieve resolution of the patient's dysphoria, anhedonia, and fatigue. CHS, cyclic episodes of nausea and vomiting often relieved with hot baths, can be a confusing emergency department presentation. Other medical presentations of heavy cannabis smoking include cough, bronchitis, lung hyperinflation, (10) as well as acute lung injury from vaping. (11) Legal (12) or employment (13) concerns related to cannabis may also generate first visits with a clinician.