Testing the Cognitive Catalyst Model with Idiographic Content: Rumination Moderates the Association between Self-Discrepancies and Depressive Symptoms

Depressive rumination, which involves repetitive thinking directed at one's depressive symptoms and the perceived causes and consequences of those symptoms, plays an important role in the onset and maintenance of depression. Recently, Ciesla, and Roberts (2002, 2007; Ciesla, Felton, & Roberts, 2011) proposed the cognitive catalyst model of depression, which posits that rumination intensifies the impact of already existing negative cognitions. Previous studies examining rumination as a moderator of cognitive content have used nomothetic conceptualizations of cognitive content. The current research replicated and extended these past studies using an idiographic conceptualization of negative cognitive content, specifically self-discrepancy theory (SDT). SDT suggests that idiographic self-guides serve to direct behavior and govern self-regulation (Higgins, 1987). Two studies based on college student samples (N = 102 and N = 107) tested the interaction between rumination and self- discrepancies in the prediction of depressive symptoms. In line with the cognitive catalyst model, Study 1 found that rumination moderated the association between actual:ideal self-discrepancies and depressive symptoms, such that self-discrepancies predicted depression more strongly among high compared to low ruminators. Study 2 found that the interaction between rumination and actual:ideal self-discrepancies was specific to predicting dysphoric mood and insomnia versus other dimensions of depressive symptoms, such as lassitude, appetite change and suicidality, and that these effects were limited to males. Results from the two studies provide further support for the cognitive catalyst model by demonstrating that rumination amplifies the association between self-discrepancies and depression and suggests that these effects may be specific to dysphoric mood and insomnia (at least for males) as opposed to other forms of depressive symptomatology.