Stability and transition likelihood of primary symptoms in adults with obsessive-compulsive disorder: A 5-year prospective follow-up study

Background: Obsessive-compulsive disorder (OCD) has a chronic course. However, limited longitudinal research exists on whether adults with OCD tend to maintain the same cluster of symptoms and how those symptoms may change over time. The present study aimed to examine the stability of primary OCD symptoms across 5 years and describe how symptoms change within individuals. Methods: 107 treatment-seeking adults with primary OCD participated in a naturalistic prospective study on the course of OCD. Primary obsessions and compulsions were assessed using the Yale-Brown Obsessive Compulsive Scale at baseline, year 2, and year 5. Markov transition probabilities were calculated to assess the likelihood of symptom change from one of the nine primary obsession categories and seven compulsion categories to another at follow-up. Results: Symptom stability varied across categories. Contamination, hoarding, symmetry, and responsibility for harm obsessions were generally stable, along with hoarding, cleaning, and checking compulsions. Conversely, somatic, aggressive, religious, sexual, and miscellaneous obsessions tended to change, along with repeating, counting, and ordering/arranging compulsions. Aggressive, religious, and sexual obsessions most often switched to one of the other two categories at follow-up. Overall, OCD symptom stability decreased over longer follow-up periods. Limitations: Symptom stability was only assessed between baseline and years 2 and 5. Therefore, possible changes between years 2 and 5 remain unclear. Conclusions: OCD symptoms are relatively stable over time; however, specific symptoms may be more likely to vary. Future research should investigate factors underlying stable and unstable symptoms, as well as the impact of treatment on symptom stability.