Reward-related neural dysfunction across depression and impulsivity: A dimensional approach.

Recent theoretical models underline reward sensitivity as a potential endophenotype for major depressive disorder. Neural and behavioral evidence reveals depression is associated with reduced reward sensitivity. However, reward dysfunction is not unique to depression, as it is also common across disorders of poor impulse control. We examined the interrelationships of depression (Depression, Anxiety, and Stress Scale [DASS-21]) and impulsivity (UPPS-P Impulsive Behavior Scale) with reward sensitivity among a large, representative sample (N = 260). ERPs were recorded to isolate two neural indicators of consummatory reward processing: initial evaluation of rewards in the 250-350 ms time window postonset of feedback (reward positivity [RewP]), and salience to monetary outcomes (P3). Significant interactions were observed between depression and impulsivity facets across these two stages of reward processing: depression and positive urgency predicted RewP amplitude to reward outcomes (win vs. loss); depression and one other impulsivity trait, (lack of) premeditation, predicted P3 amplitude to monetary outcomes. Conversely, high symptoms of depression were related to three biobehavioral profiles: (1) blunted RewP in conjunction with high positive urgency, (2) combination of blunted RewP and low (lack of) premeditation, and (3) blunted P3 to monetary wins/losses, in conjunction with low (lack of) premeditation. Findings illustrate that reward-related dysfunctions may be optimally conceptualized when examining the interactions between dimensions of internalizing and externalizing psychopathology.