To assess the effect of applying strict DSM-IV-TR frequency criteria requiring that tics be present daily or nearly every day, a sensitivity analysis was conducted to relax the frequency criterion in TS/CT Intermediate to include children with tics occurring “about once a week.” This analysis increased the TS and CT Intermediate sample by 10% (five TS and seven CT cases), but resulted in no substantial change in prevalence, gender ratios, or rates of co-occurring OCD or ADHD (Table S4, available online).
