Weighing the predictive role of neural factors for adolescent anhedonia in the presence of demographic and clinical factors.

Anhedonia, a transdiagnostic symptom of psychopathology associated with pernicious clinical course, has putative mechanisms in neural reward systems and emerges during adolescence. However, the relative contributions of neural, demographic, and clinical factors to its development are unclear. 73 adolescents (13-19 years) at varying familial risk for developing anhedonia reported demographic and clinical characteristics at study entry, reported anhedonia up to three times annually, and underwent fMRI during a monetary reward paradigm. Least absolute shrinkage and selection operator (LASSO) regression, which allows for a large number of intercorrelated predictors for feature selection, revealed that among demographic, clinical, and neural factors, 10 features predicted peak anhedonia over two years: impulsivity; activation in dorsal caudate, sub-gyral temporal lobe, and cuneus; and negative FC between the ventral striatum and six regions implicated in motor and/or decision-making aspects of reward. Neural factors explained an additional 40 % of variance above impulsivity. Findings indicate that in adolescents at risk for severe mental illness, disrupted motor and decision-making reward pathways could contribute to the development of anhedonia. Additionally, anhedonia should be defined in multiple domains, beyond mere phenomenology.