We found that a high illness severity was associated with low comorbidity rates for tic disorders, panic disorder, OCRDs, anorexia nervosa and OCPD. Our finding on tic disorders is in line with previous research in that tic-related OCD severity was either comparable (11, 96) or measured as being lower (97) than non-tic related OCD in baseline measures. In fact, a longitudinal study recorded higher rates and a shorter time to remission in youth with OCD, suggesting that developmental processes that result in a natural remission of tics possibly impact comorbid OCD outcomes as well (98).
