title: Psychopathic traits mediate the association of serotonin transporter genotype and child externalizing behavior.
abstract: Although the promoter polymorphism of the serotonin transporter (5-HTTLPR) gene is associated with externalizing behavior, its mediating pathways are unknown. Given their sensitivity to serotonin neurotransmission and unique association with attention-deficit/hyperactivity disorder (ADHD) and oppositional defiant disorder (ODD), we tested callous-unemotional (CU) traits and narcissism as separate mediators of the association of 5-HTTLPR with ADHD and ODD. We evaluated 209 5-9 year-old children with and without ADHD at baseline; approximately 2 years later (i.e., Wave 2), parents and teachers separately rated ADHD and ODD symptoms and youth self-reported antisocial behavior. Controlling for race-ethnicity and baseline ADHD/ODD, narcissism uniquely mediated predictions of multi-informant rated Wave 2 ADHD and ODD from variation in 5-HTTLPR; CU traits mediated predictions of Wave 2 ADHD from variations in 5-HTTLPR, but did not mediate the associations of 5-HTTLPR with ODD or youth self-reported antisocial behavior. Specifically, the number of 5-HTTLPR long alleles positively predicted CU traits and narcissism; narcissism was positively associated with Wave 2 ADHD and ODD symptoms, whereas CU traits were positively associated with Wave 2 ADHD. Child sex also moderated indirect effects of CU traits and narcissism, such that narcissism mediated predictions of ADHD/ODD in girls but not boys. Psychopathic traits may represent a relevant pathway underlying predictions of prospective change in ADHD and ODD from 5-HTTLPR, particularly in girls. We consider the role of psychopathic traits as a potential intermediate phenotype in genetically sensitive studies of child psychopathology. Aggr. Behav. 42:455-470, 2016. © 2016 Wiley Periodicals, Inc.
authors.affiliation: Department of Psychology, University of California, 1285 Franz Hall, Los Angeles, California.
authors.forename: Whitney A
authors.initials: WA
authors.lastname: Brammer
authors.affiliation: Department of Psychology, University of California, 1285 Franz Hall, Los Angeles, California.
authors.forename: Kristen L
authors.initials: KL
authors.lastname: Jezior
authors.affiliation: Department of Psychology, University of California, 1285 Franz Hall, Los Angeles, California.
authors.forename: Steve S
authors.initials: SS
authors.lastname: Lee
mesh_terms: D019958:Attention Deficit and Disruptive Behavior Disorders / Q000235:genetics*; D002648:Child; D002653:Child Behavior Disorders / Q000235:genetics*; D002675:Child, Preschool; D005260:Female; D006801:Humans; D008297:Male; D011446:Prospective Studies; D050486:Serotonin Plasma Membrane Transport Proteins / Q000235:genetics*; D012737:Sex Factors
chemical_list: C493230:SLC6A4 protein, human; D050486:Serotonin Plasma Membrane Transport Proteins
keywords: 5-HTTLPR; ADHD; ODD; callous-unemotional traits; narcissism