Diagnostic validity of early-onset obsessive-compulsive disorder in the Danish Psychiatric Central Register: findings from a cohort sample.

The validity and reliability of International Classification of Disease 10th revision codes for OCD in the DPCR is generally high. The subcodes for predominant obsessions/predominant compulsions are less certain and should be used with caution. The results apply for both children and adolescents and for both older and more recent cases. Altogether, the study suggests that there is a high validity of the OCD diagnosis in the Danish National Registers.