TABLE 3

Comparison of Age at PHV and Magnitude of PHV Between ADHD Cases and Non-ADHD Controls and by Cumulative Stimulant Duration

No. of SubjectsAge at PHV (y)Magnitude of PHV (cm/y)
Mean (SD)PaMean (SD)Pa
Male subjectsADHD cases15813.3 (1.1).968.2 (1.5).71
Non-ADHD controls25613.3 (1.3)8.3 (1.6)
Female subjectsADHD cases5911.0 (1.4).877.5 (1.4).80
Non-ADHD controls8711.0 (1.1)7.4 (1.2)
ADHD cases onlyCumulative stimulant duration before PHV
 Male subjectsStimulant naiveb6512.9 (1.2).0028.0 (1.5).22
Stimulant treatedc8813.5 (1.0)8.3 (1.5)
3 m–3 y2713.3 (0.9)8.4 (1.8)
≥3 y6113.6 (0.9)8.3 (1.5)
 Female subjectsStimulant naiveb3610.8 (1.5).367.5 (1.5).99
Stimulant treatedc2211.2 (1.0)7.5 (1.4)
3 m–3 y1611.1 (1.1)7.4 (1.4)
≥3 y611.3 (0.9)7.7 (1.5)
  • a 2-sample t test comparing ADHD cases with non-ADHD controls and, among the ADHD cases, stimulant naive with stimulant treated.

  • b Stimulant naive was defined as subjects on stimulants for <3 mo before the time of the PHV.

  • c 6 ADHD cases had an unknown duration of stimulant medication treatment and were not included in this subanalysis.