The form and function of depressive rumination

Rumination is a symptom of depression that refers to intense, distraction-resistant thinking. Although rumination is widely considered maladaptive, the analytical rumination hypothesis (ARH) proposes that rumination is an adaptive cognitive process where depression first promotes rumination on the causes of problems ("causal analysis"), which in turn promotes rumination on solving problems ("problem-solving analysis"). Effective problem-solving then feeds back to reduce depressive symptoms. To test this cyclical model, a scale with both problem-solving and causal analysis components is required. There are two candidates: (1) the widely used Ruminative Responses Scale (RRS); and (2) the Analytical Rumination Questionnaire (ARQ) a new scale based on the ARH. These instruments were administered to five samples (Total N = 1414) from two different cultures (Canada, Czech Republic) with different clinical statuses (nonclinical, hospitalized). Latent factor analysis of the ARQ supported the existence of both causal analysis and problem-solving analysis factors, making it suitable for testing ARH predictions. Using the ARQ we found consistent support for the predicted covariance pattern between depression, causal analysis, and problem-solving analysis. However, we found no evidence that either of the RRS factors were related to problem-solving. Moreover, we were systematically unable to detect the predicted covariance pattern between depression and the RRS factors. We conclude that the ability to detect functional relationships between depression and rumination requires the researcher to consider both function (a correct hypothesis for how rumination and depression are adaptively related to each other) and form (valid measures of those constructs). Understanding rumination as a two-stage problem-solving process may help explain why most depressive episodes eventually resolve without treatment. (C) 2018 Elsevier Inc. All rights reserved.