It appears adaptive to change one's expectations when continuously gaining expectation-disconfirming experiences; however, research has shown that people suffering from MDD have difficulty in changing their expectations after experiences that disconfirm expectations. Recently, the investigators have shown that this persistence of expectations is due to maladaptive information processing involving "cognitive immunization", defined as a cognitive reappraisal of expectation-disconfirming experiences in such a way that the individual's expectations are maintained. In view of psychotherapeutic interventions aiming to modify patients' dysfunctional expectations, effective strategies to inhibit cognitive immunization strategies need to be identified. Therefore, the aim of this study was to compare different immunization-inhibiting strategies with regard to their effectivity in enhancing expectation change. For this purpose, the investigators use a standardized experimental paradigm, which was developed and validated in a previous study.
