How Obstructed Action Efficacy Impacts Reward-Based Decision Making in Adolescent Depression: An fMRI Study.

OBJECTIVE

Disruption of reward seeking behavior by unforeseen obstacles can promote negative affect, including frustration and irritability, in adolescents. Repeated experiences of obstructed reward may in fact contribute to the development of depression in adolescents. However, the neurocognitive mechanisms whereby goal disruption impacts reward processing in adolescent depression have not yet been characterized. The present study addresses this gap by using neuroimaging and a novel paradigm to assess how incidental action obstruction impacts reward-based decision making.

METHOD

We assessed 62 unmedicated adolescents with major depressive disorder (MDD; mean age = 15.6 years, SD = 1.4 years, 67% female participants) and 68 matched healthy control participants (mean age = 15.3 years, SD = 1.4 years, 50% female participants) using functional magnetic resonance imaging (fMRI) while they played a card game in which they had to guess between 2 options to earn points, in low- and high-stake conditions. Functioning of button presses through which they made decisions was intermittently blocked, thereby blocking action efficacy.

RESULTS

Participants with MDD made fewer button press repetitions in response to action efficacy obstruction, which was more apparent in the low-stake condition (rate ratio =0.85, p = .034). During response repetition across stake conditions, MDDs exhibited higher activation in regions in the ventromedial prefrontal cortex, caudate, and putamen (F = 16.4-25.6, df=1,125; p values <.001; Hedges g = 0.85-0.98).

CONCLUSION

Adolescents with depression tend to exhibit less flexible behavioral orientation in the face of blocked action efficacy, and abnormalities in neural systems critical to regulating negative affect during reward-based decision making. This research highlights possible mechanisms relevant to understanding and treating affective dysregulation in adolescent depression.