Abstract
To the Editor
While the risk of cannabinoids in provoking psychosis is well established (Sideli and Quigley, 2019), there is little experience with cannabis vaping. Limited available research indicates cannabis vaping produces notably different pharmacodynamic effects and more intense subjective experience in users compared to traditional smoking inhalation (Spindle et al., 2018). The recent Centers for Disease Control and Prevention (CDC) investigation into hundreds of unexplained vaping-related deaths in the United States has highlighted how this emerging trend is little understood.
Recently, a backpacker presented with an unusual drug-induced psychosis. Ten days prior he and eight others were provided with a vaping pen by another traveller. It reportedly contained cannabis oil, purchased from an unknown person through Facebook. The individual took two inhalations from the vaping pen, prompting immediate, intense autoscopy and the formation of a complex delusional narrative involving premonition of a global viral pandemic originating within contaminated vaping liquid. This was followed by 24 hours of severe formal thought disorder and referential ideas requiring admission to an interstate hospital and treatment with olanzapine.
Post discharge, the backpacker began to experience intense visual flashbacks of the autoscopic experience as well as vivid nightmares, periodically challenging his returning insight. After 10 days, widespread petechial rash, lymphadenopathy and haematuria developed. The patient attributed this to treatment side effect and ceased the antipsychotic, heralding a worsening of symptoms. He presented seeking an alternative agent and was commenced on quetiapine, however was not admitted. Urine drug screen was positive for cannabinoids.
Reportedly many of the other travellers became unwell, with another member of the group requiring lengthier psychiatric admission. The backpacker had no prior psychiatric history, no family history of psychosis and had given up smoking cannabis in the traditional form roughly a decade ago.
A recent Journal of the American Medical Association (JAMA) article compared the subjective and pharmacological effects of vaporized versus smoked cannabis among infrequent users (Spindle et al., 2018). Vaping resulted in significantly higher plasma tetrahydrocannabinol (THC) compared to smoking. Higher plasma THC was positively correlated with subjective experience, which was more severe in the vaping group. Vaping was found to elicit significantly higher mean paranoia ratings, with similar findings in regard to cognitive impairment. Another recent paper has reported that vaping produces greater neurotoxicity versus smoking following acute exposure (Noble et al., 2019).
Cannabis smoking is endemic in the community. With the legal and black market supply of cannabis oil set to increase, cannabis vaping is likely to become more widespread and cases like this will potentially present more frequently. This highlights a need for further research to guide the future treatment of these patients.
Footnotes
Declaration of Conflicting Interests
The author(s) declared no potential conflicts of interest with respect to the research, authorship and/or publication of this article.
Funding
The author(s) received no financial support for the research, authorship and/or publication of this article.
