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.