Introduction: The concept of subclinical obsessive-compulsive disorder is explored using data from a "high-risk" study of offspring of persons with (OCD) and offspring of controls. Offspring with OCD were compared to those with subclinical OCD, and those without either condition. Subclinical OCD is defined as the presence of obsessions and/or compulsions without functional impairment.
Methods: Adults with OCD and their offspring 7-18 years of age were recruited through a tertiary care center psychiatric outpatient clinic, while controls (and their children) were recruited via advertisement. Parents and offspring were assessed using structured interviews and validated questionnaires at baseline and follow-up interviews.
Results: Offspring from both proband groups were pooled to create three subject groups: group 1, offspring with neither condition (n=43); group 2, offspring with subclinical OCD (n=24); and group 3, offspring with full OCD (n=11). Offspring with subclinical OCD held the middle ground for most comparisons. They were more symptomatic than offspring without either condition (group 1), but less symptomatic than subjects with OCD (group 3). Across the board, comparisons of diagnoses, Child Behavior Checklist (CBCL) results; Motor tic, Obsessions and compulsions, Vocal tic Evaluation Survey results; and Leyton Obsessional Inventory (LOI) results were associated with subject group at baseline and follow-up. In post-hoc comparisons, subjects with subclinical OCD had fewer comorbid anxiety disorders and lower CBCL internalizing scale scores at follow-up. Parents of children with OCD had higher LOI symptom and severity scores than parents in those of groups 1 or 2.
Conclusion: The findings suggest that subclinical OCD holds the middle ground between full-blown OCD and having neither condition in terms of obsessive-compulsive symptoms and severity, tics, associated mood/anxiety disorders, and general functioning. At least in persons at risk for OCD, the presence of subclinical OCD may herald the onset of OCD, though in others may be an independent condition that does not lead to full OCD.