Life stress, the dopamine receptor gene, and emerging adult drug use trajectories: a longitudinal, multilevel, mediated moderation analysis.
This study was designed to examine the prospective relations of life stress and genetic status with increases in drug use. African Americans (N = 399) in rural Georgia (Wave 1 mean age = 17 years) provided three waves of data across 27.5 months and a saliva sample from which the dopamine receptor D4 (DRD4) gene was genotyped. Multilevel growth curve modeling analysis indicated that emerging adults manifested the highest escalations in drug use when they reported high life stress and carried an allele of DRD4 with 7 or more repeats (7 + R allele). In addition, emerging adults who reported high life stress and carried the 7 + R allele evinced the largest increases in two proximal risk factors for drug use: affiliations with drug-using companions and drug use vulnerability cognitions. Furthermore, when the Gene × Environment interaction effects on the increases in affiliations with drug-using companions and vulnerability cognitions were entered into the model forecasting drug use, the Life Stress × DRD4 Status interaction on drug use became nonsignificant in the presence of the risk mechanisms. This finding provides an example of "second generation" Gene × Environment interaction research in which the interaction's effects on proximal risk mechanisms account for its effects on outcomes.
University of Georgia, Center for Family Research, 1095 College Station Road, Athens, GA 30602-4527, USA. gbrody@uga.edu
Gene H
GH
Brody
Yi-Fu
YF
Chen
Tianyi
T
Yu
Steven R H
SR
Beach
Steven M
SM
Kogan
Ronald L
RL
Simons
Michael
M
Windle
Robert A
RA
Philibert
D000293:Adolescent; D001741:Black or African American / Q000235:genetics; D000483:Alleles; D005260:Female; D059647:Gene-Environment Interaction; D020022:Genetic Predisposition to Disease; D005838:Genotype; D005845:Georgia; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D011446:Prospective Studies; D050638:Receptors, Dopamine D4 / Q000235:genetics*; D012307:Risk Factors; D057566:Self Report; D013315:Stress, Psychological / Q000235:genetics*; D019966:Substance-Related Disorders / Q000235:genetics* / Q000523:psychology; D011795:Surveys and Questionnaires; D055815:Young Adult
C493599:DRD4 protein, human; D050638:Receptors, Dopamine D4