CONTENTS
(1) What is rumination?
(2) Online information
(3) For professionals
(1) What is rumination?
Rumination has been defined as the "compulsively focused attention on the symptoms of one's distress, and on its possible causes and consequences, as opposed to its solutions" (Nolen-Hoeksema, et al., 1998). It has been implicated in the development, maintenance, and aggravation of depression, anxiety disorders, and other psychiatric disorders. Rumination often interferes with people's ability to focus on problem-solving and results in dwelling on negative thoughts about past failures.
(2) Online information
Wikipedia - Rumination
(3) For professionals
Nolen-Hoeksema, S.; S.A., Roberts J.E., Gotlib I.H. (1998). "Neuroticism and ruminative response style as predictors of change in depressive symptomatology.". Cognitive Therapy and Research. 22: 445–455.
Nolen-Hoeksema, S.; Wisco, B. E.; Lyubomirsky, S. (2008). Rethinking Rumination (PDF). Perspectives on Psychological Science. 3 (5): 400–424.
Watkins, E. R. (2008). "Constructive and unconstructive repetitive thought". Psychological Bulletin. 134 (2): 163–206.
Measurement: Response Styles Questionnaire