10 - How common is cannabinoid hyperemesis syndrome and why is it so hard to diagnose?

Abstract

Cannabinoid hyperemesis syndrome (CHS) was defined by the Rome Foundation as a functional nausea and vomiting disorder separated from cyclic vomiting syndrome (CVS) and chronic nausea vomiting syndrome. However, there is marked overlap with CVS and there is disagreement if CHS is a CVS subset instead of a distinct condition. Because of divergent diagnostic criteria used by different providers, the true prevalence of CHS is uncertain. Diagnosing CHS is challenging for many reasons, including (1) the requirement of prolonged cannabis abstinence to satisfy the best accepted criteria, (2) the observation of frequent hot-bathing behaviors in CVS patients that were once felt to be specific for CHS, (3) the prolonged clearance of cannabis metabolites from the body and likely slow reversal of cannabis effects on the brain, (4) reliable outpatient follow-up in continuity clinics, and (5) psychosocial factors pertaining to failures to stop cannabis products and stigmas associated with cannabis use. Updates to existing CHS diagnostic criteria are planned to address such deficiencies, but it is probable that some issues will not be readily solvable and patients who are unable to sustain cannabis avoidance may need to be considered as having possible or presumptive CHS.