AbstractBidirectional overlap between attention-deficit/hyper-activity disorder (ADHD) and ticdisorders has long been de-scribed. Twenty percent of individuals with ADHD may meet diagnostic criteria for a tic disorder, and more than 60 % of chil-dren ages 6–17 with Tourette’s disorder (TD) in the community had also been diagnosed with ADHD/ADD. While comorbid presentation of ADHD and tic disorders is firmly established, underlying genetic and pathophysiologic mechanisms need addi tional investigation. Inhibition is a core deficit in bothADHD and tic disorders, and research suggests a diffuse process in the brain involving corticostriatothalamicortical (CSTC) pathways in the basal ganglia, striatum, and frontal lobes. The complex presenta-tion of these patients requires comprehensive evaluation and pri-oritization of treatment goals.Most studies indicate that ADHD
places a greater burden on patients than do tics. Optimal patient outcomesmaydependonmanagement of bothADHDsymptoms and tics when they co-occur. Research in the past decade has shown that these conditions can besafely treated simultaneously. KeywordsADHD. Attention-deficit/hyperactivitydisorder. Tics.Tourette’sdisorder. Treatment.Comorbidity. Corticostriatothalamicortical (CSTC) pathways. Bidirectional overlap