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Effect of D2R, NMDAR and CB1R genetic variants associated with cannabis use and childhood trauma in first-episode psychosis in a Brazilian population

C. Loureiro, F. Corsi-Zuelli, H. Fachim, R. Shuhama, P. Menezes, C. Dalton, P. Louzada-Júnior, S. Belangero, F. Coeli-Lacchini, G. P. Reynolds, R. Lacchini, C. Del-Ben

European Psychiatry March 1, 2023 DOI: 10.1192/j.eurpsy.2023.584 (opens in new tab)

Study at a glance

AI-extracted from the abstract
Characteristics Case-control study Peer reviewed
Sample size 429
Population First-episode psychosis patients and community-based controls of both sexes aged 16 to 64 years in Brazil
Duration 3-year recruitment period
Measures Cannabis Experience Questionnaire, Childhood Trauma Questionnaire
Topics Cannabis
Key findings No single nucleotide variant among 23 tested was associated with psychosis alone, but the authors report gene-environment interactions: CNR1 rs12720071 combined with lifetime cannabis use (p<0.001) and with childhood trauma (p<0.05), and CNR1 rs7766029 when both environmental factors were modeled together (p<0.001), were associated with increased psychosis risk. The authors conclude the results support gene-environment interactions involving CNR1 variants, childhood trauma, and cannabis use in psychosis.

Abstract

Introduction: Gene-environment interactions increase psychosis risk (Gayer-Anderson et al. Soc Psychiatry Psychiatr Epidemiol 2020; 55(5):645-657). However, identifying the genetic variants involved and how they interact with environmental risk factors underlying psychosis remains challenging.

Objectives: To investigate whether there are gene-environment interactions in the relationships of childhood trauma, lifetime cannabis use, and single nucleotide variants (SNVs) of dopamine D2 receptor (D2R: DRD2), N-methyl-d-aspartate receptor (NMDAR: GRIN1, GRIN2A and GRIN2B) and cannabinoid receptor type 1 (CB1R: CNR1) with psychosis.

Methods: In a population-based case-control study nested in an incident study (STREAM, Brazil) (Del-Ben et al. Br J of Psychiatry 2019; 215(6):726-729), part of the EU-GEI consortium (Gayer-Anderson et al. Soc Psychiatry Psychiatr Epidemiol 2020; 55(5):645-657), 143 first-episode psychosis patients and 286 community-based controls of both sexes aged between 16 and 64 years were included over a period of 3 years. Twenty-three SNVs of D2R (rs1799978, rs7131056, rs6275), NMDAR (GRIN1: rs4880213, rs11146020; GRIN2A: rs1420040, rs11866328; GRIN2B: rs890, rs2098469, rs7298664), and CB1R genes (CNR1: rs806380, rs806379, rs1049353, rs6454674, rs1535255, rs2023239, rs12720071, rs6928499, rs806374, rs7766029, rs806378, rs10485170, rs9450898), were genotyped from peripheral blood DNA using a custom Illumina HumanCoreExome-24 BeadChip. Environmental adversities were evaluated using the Cannabis Experience Questionnaire (Di Forti et al. The Lancet Psychiatry 2009; 6(5):427–436) and the Childhood Trauma Questionnaire (Grassi-Oliveira et al. Rev Saude Publica 2006; 40(2):249-55). Associations between SNVs and environmental risk factors were performed using the nonparametric multifactor dimensionality reduction software (version 3.0.2).

Results: Single locus analysis showed no association among the 23 SNVs with psychosis; however, gene-environment analysis was significant for the polymorphic loci rs12720071 and rs7766029 in CNR1. The best association models were the two-factor representing by the combination of CNR1 rs12720071 with lifetime cannabis use (p<0.001), and CNR1 rs12720071 with childhood trauma (p<0.05), both suggesting an increased risk of psychosis. Additionally, when considering the interaction of both environmental factors in the same model, we found CNR1 rs7766029 to be associated with psychosis (p<0.001).

Conclusions: Our study supports the hypothesis of gene-environment interactions for psychosis involving the T allele carriers of CNR1 SNVs (rs12720071 and rs7766029), childhood trauma and lifetime cannabis use in psychosis. Disclosure of Interest None Declared

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