Mental Health Symptom Changes by Sex or Gender Before and During the COVID-19 Pandemic: A Systematic Review and Meta-Analysis.

Maladaptive, mostly negatively biased, and highly rigid self-beliefs are prominent in various mental disorders []. Humans act on their beliefs as if they reflect reality [], which makes maladaptive beliefs a key maintaining factor of mental disorders []. These beliefs are a product of our learning history and are constantly updated in the face of incoming information that deviates from expectations [–]. Maladaptive beliefs in depression often center on a pessimistic view of oneself, like one’s ability or one’s future []. When the emphasis of this internal model is strong [], one becomes insensitive to the external context, such as contradictory positive feedback information []. Negative self-beliefs are typical characteristics of depression and are maintained by negatively distorted information processing []. Accordingly, more negative belief-updating about one’s future, abilities, or social popularity has been observed in experimental settings in depression [, ]. More recently, mental disorders have been conceptualized as an interplay of maladaptive prior internal models with a maladaptive response to prediction errors [, ], which is the mismatch between the expectation of any future event and the actual outcome. The persistence of negative beliefs in depression has been related to reduced updating after positive prediction errors [], which means higher insensitivity to the context when incoming information is better than expected. Cognitive immunization against this unexpected positive information is a cognitive mechanism that hinders the change of negative beliefs [, ]. It reflects a reappraisal of unexpected feedback in a way that the initial expectation is maintained, for example, by devaluing positive feedback as an exception or by questioning its credibility. The experience of prediction errors is linked to the experience of affect []. The current affective state can influence the updating of self-beliefs [–], which, in turn, contributes to how the individual feels. This results in a recursive influence of affect and belief-updating on each other [, ]. Accordingly, the experience of more negative and less positive affect during learning has been linked to negatively biased updating of self-beliefs [, ]. Depression is characterized by predominantly negative affect []. Correspondingly, the negative learning history is particularly present in this pervasive mood disorder, which makes a negative interpretation of incoming information appear especially plausible []. This negative interpretation bias can impact the integration of incoming information and trigger particularly strong emotional responses [] in line with the negative interpretation, which further contributes to negative affect. When negative affect is experimentally induced, individuals show reduced flexibility in adjusting their beliefs in a positive direction [].