Comparison of clinical features among youth with tic disorders, obsessive-compulsive disorder (OCD), and both conditions.

The comorbidity of tic disorders (TD) and obsessive-compulsive disorder (OCD) has long been recognized in the clinical literature and appears to be bidirectional, affecting 20-60% of individuals with each disorder. Coffey et al. (1998) found that adults with TD+OCD had a more severe comorbidity profile than adults with OCD or TD alone. This exploratory study in children attempts to evaluate whether heightened diagnostic severity, increased comorbidity load, and lower functioning is more commonplace in youth with TD+OCD in comparison to either syndrome alone. Participants were 306 children (seeking clinical evaluation) with TD, OCD, or TD+OCD. Assessment consisted of a diagnostic battery (including structured diagnostic interviews and standardized parent-report inventories) to evaluate diagnostic severity, comorbid psychopathology, behavioral and emotional correlates, and general psychosocial functioning. Data from this study sample were not supportive of the premise that youth with both a tic disorder and OCD present with elevated diagnostic severity, higher risk-for or intensity-of comorbidity, increased likelihood of externalizing/internalizing symptomatology, or lower broad-based adaptive functioning. The OCD group had elevated rates of comorbid anxiety disorders and attention-deficit hyperactivity disorder (ADHD) and oppositional defiant disorder (ODD) were more prevalent among youth in the TD group. The three groups also differed on key demographic variables. Our findings suggest that, in contrast to adults, TD+OCD in children and adolescents does not represent a more severe condition than either disorder alone on the basis of diagnostic comorbidity, symptom severity, or functional impairment.