Neurological Soft Signs and Clinical Features of Tic-Related Obsessive-Compulsive Disorder Indicate a Unique Subtype

Tic-related obsessive-compulsive disorder (OCD) may be a unique OCD subtype. This study examined whether neurological soft signs (NSSs) of patients with tic-related and tic-free OCD enable discrimination of these subgroups. We used the Neurological Evaluation Scale to assess 32 patients with tic-related and 94 with tic-free OCD, as well as 84 controls. Most patients with tic-related OCD were male, with earlier illness onset and poorer insight scores than those of patients with tic-free OCD. Patients with tic-related OCD had poorer motor coordination, sensory integration, and motor sequencing than did tic-free patients. Logistic regression using NSS subscale scores predicted tic-related OCD. Patients with tic-related OCD displayed greater neurodevelopmental abnormalities than did tic-free patients. NSSs of the former group suggest the need to separate this subgroup. Our results also support the newly introduced tic-related specifier in the fifth edition of the Diagnostic and statistical manual of mental disorders.