The short (S) allele of the serotonin transporter polymorphism and acute tryptophan depletion both increase impulsivity in men.
Reduced serotonergic neurotransmission is implicated in impulsive behavior. We studied the triallelic system of the serotonin transporter gene linked polymorphic region (5-HTTLPR) and acute manipulation of serotonin together to further delineate the mechanisms by which serotonergic neurotransmission affects impulsivity. Fifty-two healthy participants (38 men and 14 women) underwent acute tryptophan depletion (ATD) or placebo in a randomized, double-blind, parallel group experiment. Impulsive response style was measured on two versions of the Continuous Performance Task (CPT), and calculated using signal detection theory. We observed a dose-dependent effect for the short (S') allele of the 5-HTTLPR on impulsive response style. Individuals who had the S'/S' genotype were more impulsive than individuals with the L/S' genotype. Participants with the L/S' genotype were more impulsive than those with the L/L genotype. ATD increased impulsivity in men, and decreased impulsivity in women. These data demonstrate for the first time that reduced serotonergic tone as a result of either 5-HTTLPR genotype, or experimental ATD, are both independently and additively, associated with elevated impulsive response style in Caucasian men.
Walderhaug
Espen
E
Department of Psychiatry, Yale University School of Medicine, West Haven, CT 06516, USA. espen.walderhaug@yale.edu
Herman
Aryeh Isaac
AI
Magnusson
Andres
A
Morgan
Michael John
MJ
Landrø
Nils Inge
NI
D000328:Adult; D000483:Alleles; D004311:Double-Blind Method; D005260:Female; D005838:Genotype; D006801:Humans; D007175:Impulsive Behavior / Q000235:genetics*; D008297:Male; D011110:Polymorphism, Genetic; D050486:Serotonin Plasma Membrane Transport Proteins / Q000235:genetics*; D012737:Sex Factors; D017603:Signal Detection, Psychological; D014364:Tryptophan / Q000172:deficiency; D044465:White People
D050486:Serotonin Plasma Membrane Transport Proteins; D014364:Tryptophan