Examining the independent effects of motivational factors and withdrawal mechanisms on functional impairment.

Motivational factors representing approach and avoidance mechanisms (i.e., behavioral inhibition system, behavioral activation system) have been implicated with depression and anxiety, and have a negative impact on functional outcomes. The independent effects of withdrawal mechanisms, anhedonia and social anxiety, have been established, but are often examined in isolation of one another. The potential modulating or additive relationship between these motivational factors and withdrawal mechanisms remains unclear. Thus, the current study examined the additive and interactive effects of trait level motivational factors and withdrawal mechanisms on impairment in key domains of life. Participants (N = 110) with depression and anxiety symptoms ranging from none to severe completed measures of behavioral inhibition (BIS) and behavioral activation (BAS), anhedonia, social anxiety, and functional outcomes. Linear regressions were conducted to assess the interactive and main effects of these factors on life functioning. While no significant interactions emerged, the main effects of anhedonia and social anxiety were stable predictors of life impairment. Additionally, while behavioral inhibition initially exhibited a significant main effect on life impairment in some of the models, this effect appeared to be accounted for by social anxiety; suggesting they measure components of the same underlying construct. These findings suggest that anhedonia and social anxiety are more stable predictors of proximal functional impairment, as we observed no evidence that the interactive relationship between motivational and withdrawal mechanisms resulted in worse functioning.