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Cannabis, Schizophrenia Risk and Genetics: A Case Report of a Patient With Homozygous Valine Catechol-O-Methyltransferase Polymorphism

Katelyn Grechuk, Heela Azizi, Vatsala Sharma, Tasmia Khan, Ayodeji Jolayemi

Cureus June 18, 2021 DOI: 10.7759/cureus.15740 (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 24-year-old female with psychotic symptoms and a diagnosis of schizophrenia after extensive cannabis use
Topics Cannabis
Key findings The authors present a 24-year-old woman who developed schizophrenia after extensive cannabis use and who carried a homozygous valine COMT polymorphism, a variant they say has been associated with predisposition to schizophrenia in cannabis users. They argue that prior studies are limited by including patients with psychosis only during intoxication or persisting after cessation, and that more research is needed to clarify the relationship.

Abstract

The question of whether cannabis can trigger schizophrenia continues to be a subject of interest. There has been an increasing focus on identifying potential genetic factors that may predispose cannabis users to develop schizophrenia. One such gene identified in many studies codes for a catechol-O-methyltransferase (COMT) enzyme polymorphism. These studies, however, are limited by the inclusion of patients displaying psychotic symptoms during cannabis intoxication and those who continue to display psychotic symptoms after its cessation. The latter is of interest in truly understanding the risk of cannabis triggering schizophrenia and more studies are needed to clarify the potential relationship. We present the case of a 24-year-old female who presented with psychotic symptoms and was diagnosed with schizophrenia after extensive cannabis use. In addition, she had a homozygous valine COMT polymorphism, a genetic variant thought to be associated with a predisposition for schizophrenia in cannabis users. We discuss the significance of our findings in understanding the relationship between cannabis use and the development of schizophrenia in genetically predisposed individuals.

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

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