Differences and similarities between obsessive and ruminative thoughts in obsessive-compulsive and depressed patients: a comparative study.

Repetitive, intrusive cognitive phenomena are central both to obsessive-compulsive patients - typically as obsessive thoughts - and to depressed patients - typically as ruminative thoughts. The objective of the present study is to compare obsessive and ruminative thoughts in non-depressed obsessive-compulsive and depressed patients. Thirty-four patients diagnosed with obsessive-compulsive disorder and 34 patients diagnosed with major depression disorder were asked to identify both a personally relevant obsessive and a personally relevant ruminative thought and to subsequently evaluate these thoughts on a modified version of the Cognitive Intrusions Questionnaire (CIQ) developed by Freeston, Ladouceur, Thibodeau, and Gagnon (1991). The CIQ assesses general descriptors, emotional reactions, appraisal and coping strategies on a nine-point Likert scale. A mixed-model ANOVA demonstrated that obsessive and ruminative thoughts are distinct cognitive processes, clearly distinguishable in form, appraisal and temporal orientation across disorders. In obsessive-compulsive patients, ruminative thoughts were more common and more emotionally distressing than predicted. In depressed patients, obsessive thoughts occurred infrequently and were not associated with high negative emotions. Clarifying similarities and differences between ruminative and obsessive thoughts and understanding their interaction might ultimately help to expand on the role of cognitive vulnerability factors in obsessive-compulsive and major depression disorder.