Preschool Children Without 7-repeat DRD4 Gene More Likely to Develop Disorganized Attachment Style

Abstract


 
 
 
 Background: A disorganized attachment style is characterized by fearful and disoriented behaviours when a child is separated from their caregiver. Its presence is an early predictor of the later development of psychopathology, including depression. This study seeks to determine the effects of one environmental factor - the incidence of low birth weight - and one genetic factor - the presence of the long (7-repeat) polymorphism of the dopamine D4 receptor (DRD4) gene - on the development of disorganized attachment between the child and the mother.
 Methods: We sampled 251 mother-child dyads from the Maternal Adversity, Vulnerability and Neurodevelopment (MAVAN) project. We measured birth weight and DRD4 genotype, and assessed attachment style using modified separation-reunion procedure.
 Results: Birth weight did not have a significant effect on disorganized attachment (b=-0.001, t(230)=0.006, p=0.910). Presence of DRD4 7-repeat polymorphism had a significant negative effect on presence of disorganized attachment style (b=-1.196, t(230)=0.411, p=0.004).
 Conclusion: Children without the DRD4 7-repeat allele were more likely to display a disorganized attachment style compared to children with the DRD4 7-repeat allele. This indicates that the 7-repeat allele of the DRD4 gene may serve as a protective factor against disorganized attachment.