Neural Markers of Familial Risk for Depression: An Investigation of Cortical Thickness Abnormalities in Healthy Adolescent Daughters of Mothers with Recurrent Depression

Having a mother with major depressive disorder (MDD) is one of the strongest predictors of depression in late adolescence and early adulthood. Despite this fact, we know little about the neural mechanisms involved in the intergenerational transmission of risk for depression. Twenty-eight never-disordered daughters of recurrent depressed mothers (high-risk) and 36 never-disordered daughters of never-depressed mothers (low-risk) were scanned using MRI. Scan data were processed to provide measurements of cortical gray matter thickness. A general linear model was conducted at each surface point to assess the main effect of familial risk on cortical structure as well as to explore the interaction of familial risk and age. High-risk girls exhibited significantly thinner cortical gray matter in the right fusiform gyrus relative to low-risk girls. Exploratory analyses indicated interactions of risk group and age in the bilateral anterior insula and right anterior cingulate cortex (ACC); whereas low-risk girls exhibited an inverse association between age and thickness, girls at high risk for depression showed the reverse pattern. Additional exploratory analyses, using scores on the Children's Sadness Management Scale, indicated that thinner gray matter in the ACC of high-risk girls was associated with greater difficulty in managing sadness. These findings indicate that anomalous reductions in the cortical thickness of the fusiform gyrus may be a marker of risk for MDD. The interaction of age and group for gray matter thickness of the insula and ACC suggests a particularly important role for these regions in risk for depression and warrants additional research in longitudinal studies.