Background: Despite long-standing clinical concerns, relatively little is k
nown about the comorbidity between attention-deficit/hyperactivity disorder
(ADHD) and tic disorders. Therefore, we examined tic disorders in an ongoi
ng prospective follow-up study of male subjects with ADHD, a sample unselec
ted for ally comorbid disorder.
Methods: One hundred twenty-eight male children and adolescents with ADHD a
nd 110 male controls were comprehensively evaluated at baseline and 4 years
later. We characterized tic disorders along with a nide range of neuropsyc
hiatric correlates, including other comorbid disorders and indices of psych
osocial function in multiple domains (school, cognitive, social, and family
).
Results: Compared with controls, subjects with ADHD showed more tic disorde
rs at baseline and more new on-sets were reported at follow-up. Attention-d
eficit/hyperactivity disorder and tic disorders appeared to be independent
in course: in contrast to low rates of ADHD remission, tic disorders mostly
remitted. The age-adjusted rate of ADHD remission was 20% and that of tic
remission, 65%. Tic disorders had little effect on the psychosocial functio
ning of subjects with ADHD.
Conclusions: These findings suggest that comorbidity with a tic disorder ha
s a limited effect on ADI-ID outcome.. However, because of the relatively s
mall sample of subjects with tic disorders, our conclusions should be consi
dered preliminary until confirmed in larger studies of medicated and unmedi
cated children with ADHD with and without tic disorders.