This study further implicates loci within HTR2A with certain forms of self-reported impulsivity and identifies candidates for future investigation from the genome-wide analyses.
We have investigated whether the functional polymorphism -1438A/G in the serotonin 5-HT<sub>2A</sub> receptor gene (HTR2A) is associated with impulsivity levels and whether there is any interaction with serum lipid levels.
This study investigated the effect of the dopamine-related polymorphism in the DRD2/ANKK1 gene (rs1800497) and a serotonin-related polymorphism in the HTR2A gene (rs6313) on associations between impulsivity, cognition, and alcohol misuse in 120 emerging adults (18-21years).
Homozygosity for the T allele of the HTR2A102T/C polymorphism was associated with lower impulsivity (P=0.03) and aggression (P=0.01) compared to TC carriers.
Although the T allele of the 5-HT2a receptor gene and the s allele of the 5-HTT gene were associated with higher levels of impulsivity, there were no main effects of 5-HT genotypes on any binge eating measure, and interactions between genotypes, impulsivity, and dietary restraint were non-significant.
Following evaluation by a self-reporting measure, it was proposed that a polymorphism in the promoter of the 5-HT(2A) receptor gene is the underlying cause of impulsive behavior; however, this hypothesis is not convincing.
Furthermore, two candidate genes for ADHD, the COMT VAL158MET and the 5-HT2aT102C polymorphisms, were tested for associations with the ASRS subscales inattention and hyperactivity/impulsivity in N = 203 healthy subjects.
These results suggest the possible involvement of the A-1438A polymorphism of the 5-HT2A receptor gene in impulsive behavior; this was evaluated using a behavioral task measure that can directly reveal the traits of human impulsive behavior.