. Author manuscript; available in PMC: 2012 Feb 1.

Published in final edited form as: J Dev Behav Pediatr. 2011 FEB-MAR;32(2):103–109. doi: 10.1097/DBP.0b013e318206d700

Table 3.

Summary of stimulant treatment characteristics of ADHD subjects, by level of IQ.

Characteristic	High IQ (N=34)	Normal IQ (N=276)	Low IQ (N=21)	P-value
Any treatment with stimulants, n (%)	27 (79.4)	207 (75.0)	19 (90.5)	0.25
No. of subjects with sufficient information regarding dates and dosages for stimulant treatment	25	199	17
Age at onset of treatment with stimulants (years)				0.97
Mean (SD)	10.3 (3.3)	10.4 (3.4)	10.2 (3.2)
Median	9.6	9.9	9.4
Range	(4.5–17.1)	(2.0–18.4)	(4.9–15.7)
Duration of treatment with stimulants (months)				0.45
Mean (SD)	46.3 (40.0)	43.1 (37.5)	33.2 (32.1)
Median	36.7	35.9	24.6
Range	(1.0–138.6)	(0.5–160.0)	(0.5–110.9)