Interaction between prenatal stress and dopamine D4 receptor genotype in predicting aggression and cortisol levels in young adults.

RATIONALE: Considerable evidence suggests that genetic factors combine with environmental influences to impact on the development of aggressive behavior. A genetic variant that has repeatedly been reported to render individuals more sensitive to the presence of adverse experiences, including stress exposure during fetal life, is the seven-repeat allele of the dopamine D4 receptor (DRD4) gene.
OBJECTIVES: The present investigation concentrated on the interplay of prenatal maternal stress and DRD4 genotype in predicting self-reported aggression in young adults. As disruption of the hypothalamic-pituitary-adrenal system has been discussed as a pathophysiological pathway to aggression, cortisol stress reactivity was additionally examined.
METHODS: As part of an epidemiological cohort study, prenatal maternal stress was assessed by maternal interview 3 months after childbirth. Between the ages of 19 and 23 years, 298 offspring (140 males, 158 females) completed the Young Adult Self-Report to measure aggressive behavior and were genotyped for the DRD4 gene. At 19 years, 219 participants additionally underwent the Trier Social Stress Test to determine cortisol reactivity.
RESULTS: Extending earlier findings with respect to childhood antisocial behavior, the results revealed that, under conditions of higher prenatal maternal stress, carriers of the DRD4 seven-repeat allele displayed more aggression in adulthood (p = 0.032). Moreover, the same conditions which seemed to promote aggression were found to predict attenuated cortisol secretion (p = 0.028).
CONCLUSIONS: This is the first study to indicate a long-term impact of prenatal stress exposure on the cortisol stress response depending on DRD4 genotype.