Background: Studies on child and adolescent obsessive-compulsive disorder (OCD) indicate that symptom severity is similar across age, but significant age differences of symptom profile and comorbid disorders have been observed. These earlier studies have yielded mixed results, are methodologically heterogenous and tend to have fairly small sample sizes. The current study examines these differences in one of the largest samples to date and the first sample outside of an English-speaking cultural context.
Methods: We compared children aged 11 years and younger to adolescents aged 12 years and older from the Nordic Long-Term Obsessive-Compulsive Disorder Treatment Study that included 269 children and adolescents with a primary diagnosis of OCD. The two groups were compared on measures of OCD severity, symptom profile, comorbid symptoms, and functional impairment.
Results: Results showed that the younger group had a poorer level of insight, higher rates of ADHD, and disruptive disorders. The older group had higher levels of mental compulsions, miscellaneous obsessions and compulsions, and self-rated functional impairment. No differences were found on the prevalence of anxiety, tic or depressive disorders between the age groups, nor on overall OCD severity.
Conclusion: Overall, differences between the age groups were found to be less than in previous research. Defining groups by age of onset and duration of illness rather than age at evaluation did not change results. Mental health services in Scandinavia are free of cost, making early intervention more accessible, which may reduce subsequent secondary problems and explain these findings.