Background: Repetitive negative thinking (RNT) is a common feature of different mental disorders in the affective spectrum. Most measures of RNT are disorder-specific and measure e.g. rumination in depression or worry in anxiety. Methods: In the Netherlands Study of Depression and Anxiety (NESDA), 1820 adults completed the Perseverative Thinking Questionnaire to assess content-independent RNT over a 3-year follow-up period. We investigated the relative stability of content-independent RNT (Perseverative Thinking Questionnaire), over time as well as the association between changes in RNT and changes in affective disorder status (Composite International Diagnostic Interview) and depressive and anxiety severity (Inventory of Depressive Symptomatology, Beck Anxiety Inventory, Fear Questionnaire). Results: In the total group, baseline RNT was strongly related to RNT three years later, while the difference between the scores at baseline and three years later was negligible. Increases and decreases in RNT were associated with the occurrence and recovery of affective disorders, respectively. Furthermore, changes in RNT between baseline and three years later were associated with corresponding changes in depression, anxiety, and avoidance symptom severity. These associations were small or negligible. Limitations: Our findings may not be representative of all affective disorders as individuals with an obsessive-compulsive disorder or bipolar disorder were excluded from our sample. Conclusions: The findings suggest that RNT is not primarily an index of disorder status or epiphenomenon of symptom severity and may constitute a relatively stable transdiagnostic person characteristic.