The divergent impact of catechol-O-methyltransferase (COMT) Val 158 Met genetic polymorphisms on executive function in adolescents with discrete patterns of childhood adversity.

PURPOSE: Catechol-O-methyltransferase (COMT) Val158 Met functional polymorphisms play a crucial role in the development of executive function (EF), but their effect may be moderated by environmental factors such as childhood adversity. The present study aimed at testing the divergent impact of the COMT Val158 Met genotype on EF in non-clinical adolescents with discrete patterns of childhood adversity.

METHODS: A total of 341 participants completed the Childhood Trauma Questionnaire, the self-reported version of the Behavior Rating Inventory of Executive Function, and self-administered questionnaires on familial function. The participants' COMT Val158 Met genotype was determined. Associations among the variables were explored using latent class analysis and general linear models.

RESULTS: We found that Val/Val homozygotes showed significantly worse performance on behavioral shift, relative to Met allele carriers (F=5.921, p=0.015, Partial η2 =0.018). Moreover, three typical patterns of childhood adversity, namely, low childhood adversity (23.5%), childhood neglect (59.8%), and high childhood adversity (16.7%), were found. Both childhood neglect and high childhood adversity had a negative impact on each aspect of EF and on global EF performance. Importantly, these results provided evidence for significant interaction effects, as adolescents with the Val/Val genotype showed inferior behavioral shift performance than Met carriers (F=6.647, p=0.010, Partial η2 =0.020) in the presence of high childhood adversity. Furthermore, there were no differences between the genotypes for childhood neglect and low childhood adversity.

CONCLUSIONS: Overall, this is the first study to show that an interaction between the COMT genotype and childhood adversity affects EF in non-clinical adolescents. These results suggest that the COMT genotype may operate as a susceptibility gene vulnerable to an adverse environment.