Brain-behavior Relationships in Depression: Linking Neural Reward Sensitivity to Ecological Momentary Assessment Ratings

Reward dysfunction is thought to be play a critical role in the pathogenesis of depression. Evidence from psychophysiological studies have implicated reduced neural deficits in reward sensitivity to depressive symptomatology. However, a critical gap in existing research is how neurobiological deficits of depression that were captured in controlled laboratory contexts map on to reward-related dysfunctions (i.e., inertia) in people’s naturalistic environments. The current study approaches this gap by integrating event- related potentials (ERPs) with ecological momentary assessment (EMA) in order to clarify brain-behavior relationships in depression. Event-related potentials were collected from a large adult sample (N = 142) during two theoretically distinct laboratory tasks: social and monetary reward. Of interest were ERPs across substages of anticipatory and consummatory phases of reward processing: cue salience (cue-P3), outcome anticipation (SPN), early outcome evaluation (RewP), and outcome salience (fb-P3). Participants also completed a 6-day EMA data collection wherein they rated their anticipatory and consummatory pleasure of social and nonsocial activities. Reduced SPN amplitude and daily EMA pleasure ratings (anticipatory and consummatory) were associated with greater depressive symptoms. Next, the results from the multilevel model analysis showed evidence of inertia. Furthermore, multiple significant interactions emerged for anticipatory pleasure: (1) two-way interplay between inertia and depression; and (2) three-way interaction between inertia, cue-P3 amplitude on monetary reward, and depression. Significant interactions for consummatory pleasure included: (1) two-way interplay between inertia and RewP amplitude on social rewards in predicting consummatory pleasure; and (2) three-way interaction between inertia, fb-P3 to positive social feedback, and depression. This is the first study to show how neural measures of reward processing map onto relevant temporal processes (inertia) in naturalistic contexts.