Table 1.

Subject characteristics at baseline

CharacteristicsPlacebo, n = 32MPH, n = 37CLON, n = 34Combination, n = 33
MPH = methylphenidate; CLON = clonidine; TS = Tourette syndrome; CMTD = chronic motor tic disorder; CVTD = chronic vocal tic disorder; ADHD = attention deficit hyperactivity disorder; OCD = obsessive–compulsive disorder; ODD = oppositional defiant disorder; MDD = major depressive disorder; GAD = generalized anxiety disorder; ASQ = Abbreviated Symptom Questionnaire; I/O = inattention/overactive; O/D = oppositional/defiant; YGTSS = Yale Global Tic Severity Scale; GTRS = Global Tic Rating Scale; C-GAS = Child Global Assessment Scale.
Age, y, mean ± SD9.7 ± 1.810.7 ± 2.09.7 ± 1.810.6 ± 1.9
Sex, % male91928573
Race, % white94819485
Sexual maturity, % pubertal 919 918
Tic disorder diagnosis, %
    TS919788100 
    CMTD 9 012 0
    CVTD 0 3 0 0
ADHD subtype, %
    Inattentive81657664
    Hyperactive/impulsive 0 3 3 3
    Combined19322133
Other psychiatric diagnoses, %
    OCD22111516
    ODD41334831
    Conduct disorder 3 8 916
    GAD 3 61216
    MDD 3 3 9 6
Prior treatment, %
    Stimulant63626245
    CLON56273230
Rating scale scores, mean ± SD
    Conners ASQ-Teacher16.0 ± 6.213.2 ± 7.316.4 ± 7.013.1 ± 5.6
    Conners ASQ-Parent18.1 ± 5.517.2 ± 6.818.9 ± 6.318.4 ± 5.9
    Iowa Conners
        I/O9.9 ± 3.28.6 ± 3.99.6 ± 3.88.4 ± 2.8
        O/D4.4 ± 4.13.6 ± 3.84.5 ± 3.32.8 ± 2.7
        Total14.4 ± 6.712.2 ± 7.114.1 ± 6.511.2 ± 4.8
    YGTSS
        Motor11.4 ± 4.711.3 ± 4.211.1 ± 4.411.6 ± 4.5
        Vocal8.9 ± 5.07.7 ± 4.79.2 ± 5.410.3 ± 4.4
        Total38.4 ± 19.840.6 ± 13.640.4 ± 20.642.8 ± 17.7
    GTRS
        Teacher8.0 ± 6.18.2 ± 6.810.0 ± 6.18.2 ± 4.9
        Parent10.2 ± 6.111.2 ± 6.610.8 ± 7.611.6 ± 6.4
    C-GAS55.0 ± 10.456.4 ± 8.253.9 ± 8.555.0 ± 9.4
Classroom observations
    On-task behavior73.9 ± 19.677.1 ± 15.376.7 ± 12.679.1 ± 18.5
    Disruptive behavior12.0 ± 19.19.3 ± 10.57.8 ± 7.914.8 ± 24.7