title: Role of monoamine oxidase A genotype and psychosocial factors in male adolescent criminal activity.
abstract: BACKGROUND
  A number of important sociological, psychological, and biological predictors of adolescent criminal behavior have been identified during the most recent decades. The aim of this study was to replicate recent findings that interactions between a polymorphism in the monoamine oxidase A (MAO-A) gene promoter region and psychosocial factors might predict male adolescent criminal activity.
  
  
  METHODS
  A cross-sectional study with a randomized sample from the total population of 16- and 19-year-olds from the county of Västmanland, Sweden. Eighty-one male adolescents, who volunteered to participate, were randomly selected from groups representing different degrees of deviant risk behavior.
  
  
  RESULTS
  The present study strongly supports the notion that carrying the 3-repeat allele of the MAO-A-gene promoter increases the risk of male adolescent criminal behavior, when interacting with psychosocial factors. No effects at all of the MAO-A genotype on adolescent criminal activity were found when MAO-A genotype was considered alone (i.e., without its psychosocial context). The explained variance of the bio-psychosocial model (controlling for MAO-A) in this study exceeded the psychosocial model by 12%.
  
  
  CONCLUSIONS
  The findings support the notion that genotype and psychosocial factors interact to precipitate male adolescent criminal behavior.
authors.affiliation: Centre for Clinical Research, Uppsala University, Central Hospital Västerås, S-721 89 Västerås, Sweden. kent.nilsson@ltvastmanland.se
authors.forename: Kent W
authors.initials: KW
authors.lastname: Nilsson
authors.forename: Rickard L
authors.initials: RL
authors.lastname: Sjöberg
authors.forename: Mattias
authors.initials: M
authors.lastname: Damberg
authors.forename: Jerzy
authors.initials: J
authors.lastname: Leppert
authors.forename: John
authors.initials: J
authors.lastname: Ohrvik
authors.forename: Per Olof
authors.initials: PO
authors.lastname: Alm
authors.forename: Leif
authors.initials: L
authors.lastname: Lindström
authors.forename: Lars
authors.initials: L
authors.lastname: Oreland
mesh_terms: D000293:Adolescent; D000294:Adolescent Behavior / Q000523:psychology; D000328:Adult; D000987:Antisocial Personality Disorder / Q000201:enzymology / Q000235:genetics / Q000523:psychology; D002649:Child Abuse / Q000523:psychology*; D003417:Criminal Psychology; D003430:Cross-Sectional Studies; D005787:Gene Frequency; D005838:Genotype; D006798:Housing; D006801:Humans; D016014:Linear Models; D008297:Male; D008995:Monoamine Oxidase / Q000235:genetics*; D011110:Polymorphism, Genetic; D011237:Predictive Value of Tests; D011401:Promoter Regions, Genetic / Q000235:genetics*; D011584:Psychology; D012091:Repetitive Sequences, Nucleic Acid; D012307:Risk Factors; D012920:Social Behavior Disorders / Q000201:enzymology / Q000235:genetics* / Q000523:psychology; D012944:Social Support
chemical_list: D008995:Monoamine Oxidase