A reduction in positive self-judgment bias is uniquely related to the anhedonic symptoms of depression

Identifying patterns of biased cognitive processing specific to depression has proved difficult. The tripartite model of mood disorders [Clark, L. A., & Watson, D. (1991). Tripartite model of anxiety and depression: psychometric evidence and taxonomic implications. Journal of Abnormal Psychology, 100, 316-336] suggests that a clearer processing 'blueprint' may emerge if depression is viewed dimensionally rather than categorically and by focusing on variations in the degree of positive, rather than negative, processing bias. To investigate this possibility, the present study examined the extent to which a reduced positive self-judgment bias previously found in depressed individuals relates to depression-specific anhedonic symptoms. Sixty participants with varying levels of anxiety and depression symptoms evaluated their own performance on a working memory task in the absence of external feedback. Overall, participants showed a positive self-judgment bias, overestimating the number of trials they had performed correctly relative to objective criteria. Consistent with the tripartite framework, the extent of this positive self-judgment bias was significantly and uniquely related to depression-specific symptoms, with the positive bias reducing as anhedonia severity increased across three different symptom measures.