Vol. 11, No. 2, 2005 Page 6
Research suggests that the risk for aggression is elevated for individuals with one or two low-activity "short" (S) variants of a region of the serotonin transporter (5-HTTP) gene, which plays a critical role in regulating the reuptake of the neurotransmitter serotonin by nerve cells (see related article, Crime Times, 2005, Vol. 11, No. 1, Page 7). A new study indicates that this gene variant may also put teens at greater risk for substance abuse.
Gilberto Gerra and colleagues compared 91 adolescents with a history of drug experimentation to 125 teenagers who had never tried illegal drugs. The researchers report that "the short-short (SS) genotype frequency was significantly higher among experimenters compared with abstinent subjects," with subjects with two short variants of the gene region being more than four times more likely to have tried illegal drugs than those with two long variants. Gerra et al. also report, "The SS genotype frequency was significantly higher among aggressive/novelty seeker experimenters with poor school achievement, compared with drug experimenters without aggressiveness and school failure."
The researchers conclude, "Our data suggest that a decreased expression of the gene encoding the 5-HTT transporter, due to "S" promoter polymorphism, may be associated with an increased availability to experiment with illegal drugs among adolescents, particularly in the subjects with more consistent aggressiveness, novelty-seeking temperament, and learning disabilities."
"Serotonin transporter promoter polymorphism genotype is associated with temperament, personality traits and illegal drug use among adolescents," G. Gerra, L. Garofano, L. Castaldini, F. Rovetto, A. Zaimovic, G. Moi, M. Bussandri, B. Branchi, F. Brambilla, G. Friso, and C. Donnini, Journal of Neural Transmission, January 24, 2005 (epub ahead of print publication). Address: G. Gerra, Centro Studi Farmaco-tossico– dipendenze, Ser. T., AUSL, Parma, Italy, ggerra@ausl.pr.it.