[Interaction between COMT gene polymorphisms and childhood trauma in adolescents with non-suicidal self-injury]

To investigate the interaction between catechol-O-methyltransferase (COMT) gene polymorphisms and childhood trauma in adolescents with non-suicidal self-injury (NSSI), and to provide a basis for the prevention and intervention of NSSI among adolescents.

A total of 84 adolescents with NSSI and 87 healthy controls were enrolled in this study. Oral saliva samples were collected for genotyping of the COMT gene at rs4680 and rs165599. Childhood Trauma Questionnaire, Behavioral Function Assessment Scale of Non-suicidal Self-injury in Adolescents, and Patient Health Questionnaire-9 Items were used for mental health assessment. A hierarchical linear regression analysis was used to examine the main effect and interactive effect of COMT gene polymorphisms at rs4680 and rs165599 and childhood trauma on NSSI. The Johnson-Neyman technique was used to identify the regions where the moderating variables had a significant impact.

The interaction between COMT gene polymorphisms at rs165599 and the subtype of emotional neglect in childhood trauma could predict NSSI in adolescents (β=0.251, t=2.329, P=0.022). As for the adolescents carrying the G/G genotype at rs165599, the high emotional neglect group had a significantly higher NSSI score than the low emotional neglect group (F=4.579, P=0.049).

Adolescents carrying the G/G genotype at rs165599 of the COMT gene may have an increase in susceptibility to NSSI in case of high emotional neglect in childhood.