A controlled study of Tourette syndrome. I. Attention-deficit disorder, learning disorders, and school problems

Tourette syndrome (TS) is a common, hereditary, neurobehavioral disorder of childhood. To determine the frequency of various behavioral manifestations, we have compared 47 random normal controls to 246 patients with TS, 17 with attention-deficit disorder (ADD), and 15 with ADD secondary to a TS gene (ADD 2(0) TS). All subjects were examined prospectively with a 425-item questionnaire based on the Diagnostic Interview Schedule and the Diagnostic and Statistical Manual of Mental Disorders (DSM III). The TS patients were divided into grade 1 (too mild to treat [17.5%]), grade 2 (requiring treatment [58.9%]), and grade 3 (severe [23.6%]). Patients in all three grades of TS were significantly different from controls for DSM III symptoms of inattention, impulsivity, and hyperactivity. Sixty-two percent of TS patients had ADD, compared with 6.3% of controls; and 48.8% had ADD with hyperactivity (ADDH), compared with 4.2% of controls. In the majority of TS patients, the natural history of the disease was to start with ADDH and 2.4 years later develop motor and vocal tics. Among TS patients, 39% had previously received medication for ADDH or behavior problems, compared with 2% of the controls. Although stimulants can occasionally exacerbate tics, there was no evidence that stimulants cause TS and they are often a valuable adjunct to the treatment of TS. It is estimated that 10%-30% of ADDH is due to or associated with the presence of a TS gene. TS patients had a significantly increased frequency of (1) attending classes for the educationally handicapped, (2) placement in classes for the severely emotionally disturbed, (3) attending any special classes, (4) severe test anxiety, (5) stuttering, (6) letter, number, or word reversal, (7) reading very slowly, and (8) poor retention of material read. A reading-problem score (dyslexia) greater than or equal to 3 was present in 26.8% of TS patients, compared with 4.2% of controls. Number reversal, word reversal, and poor retention were significant even for the TS patients with tics too mild to treat. The multiple ways in which TS impacts school performance, as well as potential remedies, are discussed.