Reward learning in pediatric depression and anxiety: preliminary findings in a high-risk sample.

BACKGROUND: Reward learning has been postulated as a critical component of hedonic functioning that predicts depression risk. Reward learning deficits have been established in adults with current depressive disorders, but no prior studies have examined the relationship of reward learning and depression in children. The present study investigated reward learning as a function of familial depression risk and current diagnostic status in a pediatric sample.
METHOD: The sample included 204 children of parents with a history of depression (n = 86 high-risk offspring) or parents with no history of major mental disorder (n = 118 low-risk offspring). Semistructured clinical interviews were used to establish current mental diagnoses in the children. A modified signal detection task was used for assessing reward learning. We tested whether reward learning was impaired in high-risk offspring relative to low-risk offspring. We also tested whether reward learning was impaired in children with current disorders known to blunt hedonic function (depression, social phobia, PTSD, GAD, n = 13) compared to children with no disorders and to a psychiatric comparison group with ADHD.
RESULTS: High- and low-risk youth did not differ in reward learning. However, youth with current anhedonic disorders (depression, social phobia, PTSD, GAD) exhibited blunted reward learning relative to nondisordered youth and those with ADHD.
CONCLUSIONS: Our results are a first demonstration that reward learning deficits are present among youth with disorders known to blunt anhedonic function and that these deficits have some degree of diagnostic specificity. We advocate for future studies to replicate and extend these preliminary findings.