Nonlinear Associations Between Co-Rumination and Both Social Support and Depression Symptoms

Co-ruminating about one's problems appears to involve both beneficial self-disclosure and harmful rumination, suggesting that moderate levels may be the most adaptive. This study used nonlinear regression to determine whether moderate levels of self-reported co-rumination in relationships with a sibling, parent, friend, and romantic partner are linked to the highest levels of self-perceived social support and lowest levels of self-reported depression symptoms in 175 emerging adults (77% female; M = 19.66 years). As expected, moderate co-rumination was associated with high social support across all four relationship types, but, somewhat unexpectedly, high levels of co-rumination were also associated with high social support. As predicted, moderate levels of co-rumination with friends and siblings were associated with low levels of depression. Contrary to hypotheses, high levels of co-rumination were associated with high depression within romantic relationships. Co-rumination with a parent did not have a linear or quadratic association with depression. These findings suggest that high co-ruminating in supportive relationships and to a lesser extent low co-ruminating in unsupportive relationships are maladaptive interpersonal processes but that co-rumination's relation to depression depends on the co-ruminating partner. Psychotherapies for depression may target these maladaptive processes by supporting clients' development of balanced self-focused negative talk.