Capsule Commentary on Fuster et al., No Detectable Association Between Frequency of Marijuana Use and Health or Healthcare Utilization Among Patients Who Screen Positive for Drug Use

Abstract

The risks and benefits of marijuana have been the subject of vigorous debate for many years. The observational study by Fuster et al.1 provides us with some insight into the risks, or lack thereof. The researchers studied a cohort of 589 primary care patients who screened positive for recent illicit or nonmedical prescription drug use. As would be expected, marijuana was the most commonly used drug, with 84 % reporting use in the past 3 months—almost one-third of these users reported daily use. The researchers found no association between marijuana use and hospitalization, emergency department utilization or quality of life. Aside from the usual limitations of observational research, the biggest problem with this study was that it included only drug users and did not include a comparison group of non-users. Nevertheless, it raises questions about the harms of marijuana use, particularly among individuals who use other drugs. Previous research has largely failed to find significant harms from marijuana use.2,3 The most concerning findings to date have been associations between marijuana use among youth and subsequent psychotic illness,4 and between acute use and motor vehicle collisions.5 While the Federal Government classifies marijuana as a high-risk substance, it is clear that the risks associated with its use are less than the two most commonly used (and legal) substances: alcohol and tobacco. How should clinicians use this information? When assessing a patient who uses marijuana, it is probably best to use a patient-centered approach. Blanket statements condemning its use or exaggerated claims regarding harms are unlikely to have any effect and only serve to reduce clinician’s credibility. It is reasonable to counsel younger users on the risks of psychotic illness and to warn drivers on the risk of collisions when under the influence. For others, it is probably best to assess the effect marijuana use has on their lives and to focus our efforts on those who show evidence of harm.