title: Pathways to age of onset of heroin use: a structural model approach exploring the relationship of the COMT gene, impulsivity and childhood trauma.
abstract: BACKGROUND
  The interaction of the association of dopamine genes, impulsivity and childhood trauma with substance abuse remains unclear.
  
  
  OBJECTIVE
  To clarify the impacts and the interactions of the Catechol -O-methyltransferase (COMT) gene, impulsivity and childhood trauma on the age of onset of heroin use among heroin dependent patients in China.
  
  
  METHODS
  202 male and 248 female inpatients who meet DSM-IV criteria of heroin dependence were enrolled. Impulsivity and childhood trauma were measured using BIS-11 (Barratt Impulsiveness Scale-11) and ETISR-SF (Early Trauma Inventory Self Report-Short Form). The single nucleotide polymorphism (SNP) rs737866 on the COMT gene-which has previously been associated with heroin abuse, was genotyped using a DNA sequence detection system. Structural equations model was used to assess the interaction paths between these factors and the age of onset of heroin use.
  
  
  RESULTS
  Chi-square test indicated the individuals with TT allele have earlier age of onset of heroin use than those with CT or CC allele. In the correlation analysis, the severity of childhood trauma was positively correlated to impulsive score, but both of them were negatively related to the age of onset of heroin use. In structure equation model, both the COMT gene and childhood trauma had impacts on the age of onset of heroin use directly or via impulsive personality.
  
  
  CONCLUSIONS
  Our findings indicated that the COMT gene, impulsive personality traits and childhood trauma experience were interacted to impact the age of onset of heroin use, which play a critical role in the development of heroin dependence. The impact of environmental factor was greater than the COMT gene in the development of heroin dependence.
authors.affiliation: Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
authors.forename: Ting
authors.initials: T
authors.lastname: Li
authors.forename: Jiang
authors.initials: J
authors.lastname: Du
authors.forename: Shunying
authors.initials: S
authors.lastname: Yu
authors.forename: Haifeng
authors.initials: H
authors.lastname: Jiang
authors.forename: Yingmei
authors.initials: Y
authors.lastname: Fu
authors.forename: Dongxiang
authors.initials: D
authors.lastname: Wang
authors.forename: Haiming
authors.initials: H
authors.lastname: Sun
authors.forename: Hanhui
authors.initials: H
authors.lastname: Chen
authors.forename: Min
authors.initials: M
authors.lastname: Zhao
mesh_terms: D000328:Adult; D054523:Adult Survivors of Child Abuse / Q000523:psychology*; D017668:Age of Onset; D000483:Alleles; D002394:Catechol O-Methyltransferase / Q000235:genetics*; D005260:Female; D005787:Gene Frequency; D059647:Gene-Environment Interaction; D005838:Genotype; D006556:Heroin Dependence / Q000235:genetics* / Q000523:psychology; D006801:Humans; D007175:Impulsive Behavior / Q000235:genetics* / Q000523:psychology; D007297:Inpatients; D008016:Life Change Events; D008297:Male; D008954:Models, Biological; D010551:Personality / Q000235:genetics; D020641:Polymorphism, Single Nucleotide
chemical_list: D002394:Catechol O-Methyltransferase