Lower neural value signaling in the prefrontal cortex is related to childhood family income and depressive symptomatology during adolescence

Lower family income during childhood is related to increased rates of adolescent depression, though the specific mechanisms are poorly understood. Evidence suggests that individuals with depression demonstrate hypoactivation in brain regions involved in reward learning and decision-making processes (e.g., portions of the prefrontal cortex). Separately, lower family income has been associated with neural alterations in similar regions. We examined associations between family income, depression, and brain activity during a reward learning and decision-making fMRI task in a sample of adolescents (full n=94; usable n=78; mean age=15.4 years). We identified neural regions representing 1) expected value (EV), the learned subjective value of an object, and 2) prediction error, the difference between EV and the actual outcome received. Regions of interest related to reward learning were examined in connection to childhood family income and parent-reported adolescent depressive symptoms. As hypothesized, lower activity in the subgenual anterior cingulate (sACC) for EV in response to approach stimuli was associated with lower childhood family income, as well as greater symptoms of depression measured one-year after the neuroimaging session. These results are consistent with the hypothesis that lower early family income leads to disruptions in reward and decision-making brain circuitry, which leads to adolescent depression.