Abnormal processing of social feedback is an important contributor to social dysfunction in depression, however the exact mechanisms remain unclear. One important factor may be the extent to which social processing depends on expectations, in particular whether social feedback confirms or violates expectations.

To answer this question, we studied behavioral and brain responses during the evaluative processing of social feedback in 25 individuals with subthreshold depression (SD) and 25 healthy controls (HCs). Participants completed a Social Judgment Task in which they first indicated expectation about whether a peer would like them or not, and then received peer's feedback indicating acceptance or rejection.

Individuals with SD who reported greater depressive symptoms gave fewer positive expectations. Compared to HCs, individuals with SD showed reduced activation in the medial prefrontal cortex when expecting positive feedback. They also exhibited increased dorsal anterior cingulate cortex after receipt of unexpected social rejection, and reduced ventral striatum activity after receipt of unexpected social acceptance.

The observed alternations are specific to unexpected social feedback processing and highlight an important role of expectancy violation in the brain dysfunction of social feedback perception and evaluation in individuals at risk for depression.

Research has revealed that negative expectations impact depressive symptoms. However, research on the change of dysfunctional expectations in depression is lacking so far. Therefore, the present research aimed to fill this gap by testing the hypothesis that people with the major depressive disorder (MDD), contrary to healthy individuals, maintain their expectations despite experiences that positively disconfirm expectations. Further, it was hypothesized that cognitive immunization (a cognitive reappraisal of the disconfirming evidence) is a mechanism underlying the persistence of expectations.

In Study 1, we compared individuals with MDD (N = 58) to healthy individuals (N = 59). Participants worked on the same performance test and received standardized feedback that either confirmed or disconfirmed their initial performance expectations. In Study 2, we investigated the effects of cognitive immunization on expectation change among 59 individuals reporting elevated levels of depression by varying the appraisal of expectation-disconfirming feedback.

Results from Study 1 show that in the expectation-disconfirming condition, healthy individuals changed their expectations, whereas individuals with MDD did not. No such difference between the two groups was found for expectation-confirming feedback. Results from Study 2 indicated that varying cognitive immunization impacted expectation change, thus suggesting a crucial role of cognitive immunization in expectation change.

These two studies indicated that individuals suffering from depression have more difficulties in changing their expectations after disconfirming experiences than do healthy individuals, and cognitive immunization might be a core mechanism underlying expectation persistence. Therefore, psychotherapeutic interventions should aim to inhibit cognitive immunization processes to enhance expectation change.