Trait approach and avoidance motivation are higher-order individual differences that are related to personality, emotional temperament, and basic drives (i.e., sensitivity to pain and pleasure). Previous research has shown that approach and avoidance motivation are related to depression and anxiety, but the question of how trait motivation affects these dimensions of psychopathology has yet to be answered. The present study aimed to begin to answer this question by identifying potential neural mechanisms that could explain this relationship. Dimensional measures of depression (i.e., depressive loss of interest, depressive low positive affect) and anxiety (i.e., anxious arousal, anxious apprehension) were gathered at two time-points. Neural data and measures of trait approach and avoidance were gathered at the first time point. Trait avoidance motivation was associated with increases in both dimensions of depression and anxious arousal, and trait approach motivation was associated with decreases in depressive low positive affect. An adaptive balance between approach and avoidance motivation (i.e., more approach relative to avoidance) was generally associated with decreases in both dimensions of depression and anxious arousal. Neural activity during the anticipation of punishments and the receipt of disappointing feedback mediated the relationship between this adaptive balance and changes in anxious arousal and depressive low positive affect, respectively. Regions that mediated changes in anxious arousal were part of neural networks associated with self-referential processing, inhibition, and the integration of emotional information with goals (e.g., default mode network). Regions that mediated changes in depressive low positive affect were associated with processing the somatic aspects of emotion. Results suggest that those with an adaptive balance between trait approach and avoidance motivation engage with negative or disappointing information and that this engagement is protective against worsening symptoms of depressive low positive affect and anxious arousal. These findings are in line with theory undergirding therapeutic approaches that encourage engaging with feared or unpleasant information as opposed to avoiding it. Furthermore, these findings show that trait approach and avoidance motivation are associated with a broad network of brain regions related to important aspects of emotional experience and that these networks may be fruitful targets for future mechanistic and therapeutic research
