A common neural signature between genetic and environmental risk

Not everyone is equally likely to experience mental illness. What is the contribution of an individuals genetic background, or experiences of childhood adversity, to that likelihood? And how do these dimensions of risk interact at the level of the brain? We investigated the relationship between genetic liability for mental illness, childhood adversity, and cortico-limbic connectivity in a large developmental sample drawn from the ABCD cohort. First, we used Canonical Correlation Analysis to uncover two genetic dimensions of mental health using polygenic risk scores for ADHD, Anxiety, Depression, and Psychosis. The first dimension represented liability for broad psychopathology which positively correlated with adversity, while the second represented neurodevelopmental-specific risk which negatively interacted with adversity. Next, we investigated the cortico-limbic signature of adversity and genetic liability using Partial Least Squares. We found that the neural correlates of adversity broadly mirrored those of genetic liability, with adversity capturing most of the shared variance. These novel findings suggest that genetic and environmental risk overlap in the neural connections that underlie behavioural symptomatology.