Quantitative and qualitative aspects of obsessive-compulsive behaviour in children with attention-deficit hyperactivity disorder compared with tic disorder

Objective: Within the framework of associated psychopathology in child psychiatric disorders, this study focused on quantitative and qualitative aspects of obsessive-compulsive behaviour (OCB) in both attention-deficit hyperactivity disorder (ADHD) and chronic tic disorder/Tourette's disorder (TD). Method: Forty-two healthy controls, 41 children with ADHD and 38 children with TD, aged 9-13 years, were investigated using the Leyton Obsessional Inventory - Child Version (LOI-CV), the Child Behaviour Checklist (CBCL) and an expert-rated structured parent interview to reflect a cross-informant view of OCB. Results: Unexpectedly, self-reports of children with ADHD rather than children with TD showed the highest OCB scores in the LOT-CV. Qualitatively, ADHD-related OCB focused on the item subsets concerning 'dirt and contamination', 'repetition', 'overconscientiousness', and 'hoarding'. In the parent-rated CBCL, similar levels of OCB were reported for ADHD and TD patients. In contrast, only children with TD showed clinically relevant OCB according to expert ratings. Conclusion: Not only young TD patients but also children with ADHD should be investigated and monitored carefully for quantitative and qualitative aspects of OCB comorbidity.