title: COMT Val(158)Met genotype and cannabis use in people with an At Risk Mental State for psychosis: Exploring Gene x Environment interactions.
abstract: Epidemiological and retrospective studies suggest a cannabis x catechol-O-methyltransferase (COMT) Val(158)Met interaction effect on development of psychosis. The aim of this study was to examine this interaction and its association with severity of subclinical symptoms in people with an At Risk Mental State (ARMS) for psychosis.
  
  
  
  Severity of symptoms, cannabis use and genotype were assessed at baseline in 147 help-seeking young adults who met the ARMS criteria and agreed to participate in the Dutch Early Detection and Intervention (EDIE-NL) trial.
  
  
  
  Cannabis use and COMT Val-allele showed an interaction effect in ARMS subjects. Subjects who were weekly cannabis users at some point prior to entering the study showed more severe positive symptoms. This effect increased if they were carriers of the COMT Val-allele and even more so if they were homozygous for the Val-allele.
  
  
  
  Our results suggest that the COMT Val(158)Met polymorphism moderates the effect of regular cannabis use on severity of subclinical psychotic symptoms.
authors.affiliation: Department of Psychiatry, Academic Medical Center, Amsterdam, the Netherlands. Electronic address: d.h.nieman@amc.nl.
authors.forename: Dorien H
authors.initials: DH
authors.lastname: Nieman
authors.affiliation: Department of Psychiatry, Academic Medical Center, Amsterdam, the Netherlands.
authors.forename: Sara
authors.initials: S
authors.lastname: Dragt
authors.affiliation: Department of Psychiatry and Psychology, Maastricht University, the Netherlands.
authors.forename: Esther D A
authors.initials: EDA
authors.lastname: van Duin
authors.affiliation: Department of Psychiatry, Academic Medical Center, Amsterdam, the Netherlands.
authors.forename: Nadine
authors.initials: N
authors.lastname: Denneman
authors.affiliation: Department of Psychiatry, Academic Medical Center, Amsterdam, the Netherlands.
authors.forename: Jozefien M
authors.initials: JM
authors.lastname: Overbeek
authors.affiliation: Department of Psychiatry, Academic Medical Center, Amsterdam, the Netherlands.
authors.forename: Lieuwe
authors.initials: L
authors.lastname: de Haan
authors.affiliation: Department of Early Psychosis, Dijk en Duin Psychiatric Institute, Castricum, The Netherlands.
authors.forename: Judith
authors.initials: J
authors.lastname: Rietdijk
authors.affiliation: Department of Psychiatry, Parnassia Psychiatric Institute, The Hague, the Netherlands.
authors.forename: Helga K
authors.initials: HK
authors.lastname: Ising
authors.affiliation: Bascule, Child and Adolescent Psychiatry, Amsterdam, the Netherlands.
authors.forename: Rianne M C
authors.initials: RMC
authors.lastname: Klaassen
authors.affiliation: Department of Psychiatry and Psychology, Maastricht University, the Netherlands.
authors.forename: Thérèse
authors.initials: T
authors.lastname: van Amelsvoort
authors.affiliation: Friesland Mental Health Service, Department of Education and Research, the Netherlands.
authors.forename: Lex
authors.initials: L
authors.lastname: Wunderink
authors.affiliation: Department of Psychiatry, Parnassia Psychiatric Institute, The Hague, the Netherlands; VU University and EMGO(+) Institute for Mental health and Care Research, Amsterdam, the Netherlands.
authors.forename: Mark
authors.initials: M
authors.lastname: van der Gaag
authors.affiliation: Department of Psychiatry, Academic Medical Center, Amsterdam, the Netherlands; Department of Psychiatry and Psychology, Maastricht University, the Netherlands.
authors.forename: Don H
authors.initials: DH
authors.lastname: Linszen
mesh_terms: D002188:Cannabis; D002394:Catechol O-Methyltransferase / Q000235:genetics*; D005260:Female; D059647:Gene-Environment Interaction; D020022:Genetic Predisposition to Disease; D005838:Genotype; D060005:Genotyping Techniques; D006801:Humans; D008297:Male; D008385:Marijuana Smoking / Q000235:genetics* / Q000523:psychology*; D011110:Polymorphism, Genetic; D011569:Psychiatric Status Rating Scales; D011618:Psychotic Disorders / Q000150:complications / Q000235:genetics* / Q000523:psychology*; D012720:Severity of Illness Index; D055815:Young Adult
chemical_list: C588010:COMT protein, human; D002394:Catechol O-Methyltransferase
keywords: At Risk Mental State; COMT Val(158)Met; Cannabis; GxE interaction; Psychosis