Distinct trajectories of long‐term symptom severity in pediatric obsessive–compulsive disorder during and after stepped‐care treatment

Background: First-line treatments for pediatric obsessive–compulsive disorder (OCD) include exposure-based cognitive-behavioral therapy (CBT) and selective serotonin reuptake inhibitors (SSRIs). No studies have thus far identified distinct classes and associated predictors of long-term symptom severity during and after treatment. Yet, these could form the basis for more personalized treatment in pediatric OCD. Method: The study included 269 OCD patients aged 7−17 years from the Nordic Long-term OCD Treatment Study (NordLOTS). All participants received stepped-care treatment starting with 14 weekly sessions of manualized CBT. Nonresponders were randomized to either prolonged CBT or SSRIs. Symptom severity was assessed using the Children's Yale-Brown Obsessive-Compulsive Scale at seven time points from pre- to post-treatment and over a three-year follow-up. Latent class growth analysis (LCGA) was performed to identify latent classes of symptom severity trajectories. Univariate and multivariate analyses were used to detect differences between classes and identify predictors of trajectory class membership including several clinical and demographic variables. Trial registry: Nordic Long-term Obsessive-Compulsive Disorder (OCD) Treatment Study; www.controlled-trials.com; ISRCTN66385119. Results: Three LCGA classes were identified: (a) acute, sustained responders (54.6%); (b) slow, continued responders (23.4%); and (c) limited long-term responders (21.9%). Class membership was predicted by distinct baseline characteristics pertaining to age, symptom severity, contamination/cleaning and anxiety symptoms. Conclusions: The LCGA suggests three distinct trajectory classes of long-term symptom severity during and after treatment in pediatric OCD with different clinical profiles at pretreatment. The results point to required clinical attention for adolescent patients with contamination/cleaning and anxiety symptoms who do not show convincing responses to first-line treatment even though they may have reached the established cutoff for treatment response.