Associations Between Dopamine D2 Receptor (DRD2) Gene, Maternal Positive Parenting and Trajectories of Depressive Symptoms from Early to Mid-Adolescence

Using data from the Longitudinal Study of Chinese Children and Adolescents (LSCCA), this study is the first to examine the roles of the dopamine D2 receptor (DRD2) gene polymorphisms (i.e., TaqIA and A241G) and maternal positive parenting at ages 10 and 11 years in the trajectories of depressive symptoms from early to mid-adolescence (ages 11 to 16 years). In a sample of 1090 Chinese adolescents (50% girls), three trajectories of depressive symptoms were identified: (i) low-stable (36.1%), (ii) moderate-increasing (44.5%), and (iii) high-increasing (19.4%). A241G AA homozygotes and youth exposed to lower levels of maternal positive parenting were both at increased odds to follow the high-increasing vs. low-stable trajectory. Moreover, the A241G polymorphism interacted with maternal positive parenting to distinguish the moderate-increasing trajectory from the high-increasing and the low-stable trajectories. For A241G G-allele carriers, but not AA homozygotes, exposure to high quality of maternal parenting decreased the odds to follow the high-increasing vs. moderate-increasing trajectory of depressive symptoms. For AA homozygotes, but not G-allele carriers, high quality of maternal parenting increased the odds to follow the low-stable vs. moderate-increasing trajectory. The DRD2 TaqIA polymorphism had neither a direct nor an interactive effect with maternal positive parenting on trajectory membership. The current findings highlight the importance of investigating gene-by-environment interactions (G x E) in trajectories of depressive symptoms over adolescence, and support a developmental versus static nature of G x E effects.