Blunted neural effects of perceived control on reward feedback in major depressive disorder

Blunted reward processing has emerged as an endophenotype of major depressive disorder (MDD), but mechanistic understanding for this deficit remains elusive. The current event-related potential study examined whether this aberration is driven by the blunted effect of perceived control on reward processing.

We adapted a well-validated gambling task in which perceived control was exercised by choice in 29 individuals with current MDD and 31 healthy controls. We examined the reward positivity in response to personally chosen versus passively received rewards.

We found that MDD patients relative to healthy controls exhibited a blunted reward positivity when rewards were delivered following voluntary choices but not when they were delivered following passive choices. This pattern was not observed during the relatively late stage, as indexed by the P300, of feedback processing.

The current findings may be confounded with medication and anxiety.

These findings suggest that deficient reward processing in MDD is attributable to the deficiency in boosting reward responsivity by perceived control exercised by choice.