Intact Motivation in Major Depression: Normative Responsiveness to Action-Effectiveness Demonstrated in a Clinical Sample

Abstract

Ultimately, motivation enables survival through goal-directed behaviour and is evident through the direction and force of action. While a plethora of candidate responses are generated by the brain, response-selection mechanisms are responsible for evaluating and selecting the most adaptive course of action given the current context. Although motivation is known to be modulated by tangible rewards (such as food or monetary gain), substantial evidence has accumulated to suggest that both the direction and speed of responding can be modulated by feedback indicating mere influence over the environment or 'pure effectiveness' (e.g., Hemed et al., in press; Wen et al., 2018). In general, clinically depressed individuals are characterized as being less-motivated and less-active, both motorically and mentally (Sobin & Sackeim, 1997). The current study examines whether people diagnosed with Major Depressive Disorder (MDD) are similarly sensitive to (and are motivated by) effectiveness-feedback as healthy individuals are. Clinically depressed participants (N=75) performed a task in which their responses either led to action-effects or did not (i.e. effectiveness-feedback). The results show that effectiveness-feedback motivated individuals suffering from MDD, at least as strong as previously established in healthy individuals. These results suggest that the motivational system is fully activated by relevant effectiveness-feedback in MDD and imply that the motivational deficit in this condition is either limited to an outcome or goal-relevant feedback or other desired-outcome related processes. A more radical conclusion would be that a motivational deficit per-se is not a defining feature of this condition.