What is the difference between the ruminations of depression and the obsessions of OCD?
Morbid preoccupations (sometimes called ruminations) of depression can be mislabeled as obsessional thinking. The depressed patient typically dwells on matters that are meaningful to most people (e.g., one’s accomplishments or other measures of self-worth), but the patient’s perceptions or interpretations of these events and issues are colored by the depressed mood. In contrast to obsessions, depressed patients usually defend morbid preoccupations as realistic concerns. Another difference is that a depressed patient often is preoccupied with past mistakes and regrets, whereas the person with OCD is more concerned about recent events or averting future harm.
