Table 1

Participant demographic and clinical characteristics

CharacteristicAll participants
n = 92
Methylphenidate response
n = 67
ADHD
n = 67
Control
n = 25
p valueResponders
n = 44
Nonresponders
n = 23
p value
Age, yr9.76 ± 2.5110.00 ± 2.500.699.45 ± 2.3710.35 ± 2.720.17
Female, n (%)13 (19.4)14 (56)0.0029 (20.5)4 (17.4)0.76
IQ107.79 ± 13.22116.92 ± 10.800.003107.52 ± 12.33108.30 ± 15.070.82
ADHD rating scale (pretreatment)
 Inattentive15.03 ± 5.613.04 ± 3.97< 0.00115.68 ± 5.9413.78 ± 4.800.19
 Hyperactive–impulsive10.87 ± 5.421.36 ± 1.63< 0.00111.20 ± 5.6910.22 ± 4.930.48
Continuous Performance Test (pretreatment)
 Omission error65.21 ± 20.7950.80 ± 6.890.00164.57 ± 20.2566.43 ± 22.210.73
 Commission error63.85 ± 17.3257.56 ± 14.640.1164.00 ± 17.5263.57 ± 17.320.92
Final methylphenidate dose, mg32.45 ± 11.9732.61 ± 11.2432.13 ± 13.540.88
Final methylphenidate dose, mg/kg0.92 ± 0.250.98 ± 0.250.81 ± 0.220.01
  • ADHD = attention-deficit/hyperactivity disorder.

  • Values are mean ± standard deviation unless otherwise specified.