Depressive Rumination and Co-Morbidity: Evidence for Brooding as a Transdiagnostic Process.

A sample of 116 patients with unipolar mood disorders referred to a specialist research clinic were assessed to investigate (a) whether rumination is a transdiagnostic process that is related to co-morbid Axis I and II symptoms and diagnosis in depressed patients; (b) whether common findings in the depressive rumination literature could be replicated in a recurrent depressed sample. Consistent with the transdiagnostic hypothesis, rumination was positively associated with both depression and anxiety, brooding was related to co-morbid obsessive-compulsive disorder and generalized anxiety disorder, and rumination was associated with traits associated with borderline personality disorder, most notably self-report of unstable relationships and inconsistent sense of self. As predicted, rumination was equivalent in currently depressed and formerly depressed patients, suggesting that rumination is not simply dependent on mood state or clinical status. As predicted, the brooding subtype most strongly correlated with depressed and anxious symptoms, consistent with previous observations that brooding is the more maladaptive form of rumination. As predicted, rumination was associated with reports of sexual abuse. Inconsistent with previous findings, there was no gender difference in rumination.