Youth genetic vulnerability to maternal depressive symptoms: 5-HTTLPR as moderator of intergenerational transmission effects in a multiwave prospective study

Background Maternal depressive symptoms are a strong predictor of increases in depressive symptoms in offspring, yet knowledge of individual differences that may moderate the association between youth and maternal symptoms is still relatively scant. Youth genetic susceptibility to maternal depressive symptoms in particular is a nearly unexplored area of research. Methods This study used a multiwave prospective design and lagged hierarchical linear modeling analyses to examine whether youth 5-HTTLPR genotype moderated the longitudinal association between mother and youth depressive symptoms in a community sample (N = 241 youth). Maternal and youth symptoms were assessed every 3 months over 1 year (five waves of data). Results Youth 5-HTTLPR interacted with idiographic elevations in maternal depressive symptoms (elevations relative to mothers' average level of symptoms) to predict prospective increases in youth symptoms 3 months later. Youth with the SS genotype experienced greatest increases in depressive symptoms when exposed to elevations in maternal symptoms. Youth 5-HTTLPR did not interact with maternal nomothetic elevations in depressive symptoms (severity of symptoms compared to the sample as a whole). Conclusion These findings advance knowledge on genetic susceptibility for intergenerational transmission of depression between mothers and their children.