Cannabis Dopaminergic Effects Induce Hallucinations in a Patient with Parkinson's Disease.
Katie Pizzolato, David Thacker, Nicole del Toro-Pagán, Abeer Hanna, Jacques Turgeon, Adriana Matos, Nishita Amin, Veronique Michaud
Medicina (Kaunas, Lithuania) October 14, 2021 DOI: 10.3390/medicina57101107 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Case study Case report Peer reviewed |
|---|---|
| Sample size | 1 |
| Population | A 57-year-old male with Parkinson's disease and chronic back pain |
| Intervention | Cannabis |
| Topics | Cannabis |
| Keywords | Comt Cyp2c9 Parkinson’s disease Hallucinations Pharmacogenomics |
| Key findings | The authors suggest that cannabis use alongside dopamine-promoting Parkinson's drugs, especially in a patient carrying COMT and HTR2A variants, may increase the risk of vivid hallucinations; the patient's hallucinations slowly dissipated after cannabis was discontinued. They argue that herb-drug interactions and pharmacogenomic data should be part of medication safety reviews. |
Abstract
Cannabis products that contain the tetrahydrocannabinol (THC) cannabinoid are emerging as promising therapeutic agents for the treatment of medical conditions such as chronic pain. THC elicits psychoactive effects through modulation of dopaminergic neurons, thereby altering levels of dopamine in the brain. This case report highlights the complexity associated with medicinal cannabis and the health risks associated with its use. A 57-year-old male with Parkinson's disease was experiencing worsening tremors and vivid hallucinations despite therapy optimization attempts. It was discovered that the patient took cannabis for chronic back pain, and a pharmacogenomics (PGx) test indicated the presence of variants for the COMT and HTR2A genes. These variants could increase dopamine levels and predispose patients to visual hallucinations. Once the cannabis was discontinued, the patient's hallucinations began to slowly dissipate. Cannabis use continues to expand as it gains more acceptance legally and medicinally, but cannabis can affect the response to drugs. This patient case suggests that cannabis use in combination with dopamine-promoting drugs, especially in a patient with genetic variants, can increase the risk for vivid hallucinations. These conditions support the importance of considering herb-drug interactions and PGx data when performing a medication safety review.
Comparable studies
Other case reports and case series on cannabis, most cited first.
| Study | Year | Design | Participants |
|---|---|---|---|
| Hallucinogen persisting perception disorder after psilocybin consumption: a case study 18-year-old man with HPPD after mixed psilocybin and cannabis intoxication | 2005 | Case study | n = 1 |
| Cannabis‐induced Koro in Americans American men aged 22-26 with years of cannabis experience who reported negative... | 2001 | Case series | n = 3 |
| “Hallucinations” Following Acute Cannabis Dosing: A Case Report and Comparison to Other Hallucinogenic Drugs Healthy 30-year-old male | 2018 | Case study | n = 1 |
| Hallucinogen persisting perception disorder: A literature review and three case reports Patients with hallucinogen persisting perception disorder | 2018 | Case series | n = 3 |
| Cannabis Psychosis in Young Psychiatric Inpatients Consecutive psychiatric hospital admissions of patients aged 35 and under | 1986 | Case study | n = 25 |
Citations in the library
Cites 2
- Cognitive Impairment Induced by Delta9-tetrahydrocannabinol Occurs through Heteromers between Cannabinoid CB1 and Serotonin 5-HT2A Receptors PLoS Biology July 9, 2015
- COMT Val158Met moderation of cannabis‐induced psychosis: a momentary assessment study of ‘switching on’ hallucinations in the flow of daily life Acta Psychiatrica Scandinavica September 19, 2008