Summary

Cannabinoid hyperemesis syndrome is a rare, recently described, clinically diagnosed condition that is characterised by a chronic history of cannabis use, cyclic nausea and vomiting, symptomatic relief with hot water bathing, and resolution with cessation of use. We present a case of this syndrome concurrent in a patient with bipolar mania. We suggest that a 3-week period of vomiting in the context of this syndrome contributed to the precipitation of a manic episode by lowering mood stabiliser serum levels, and that this syndrome will have significant consequences for the patient's mental health.