Table 1.

Sample characteristics at baseline.

	STN			Exposed
	N = 19			N = 25
				EST (N = 14)			LST (N = 11)
	Mean	SD	Range	Mean	SD	Range	Mean	SD	Range
Age (y)	29.71	5.02	23–39	27.32	3.28	23–35	30.36	6.08	24–40
Educational levela	5.79	0.86	4–7	5.15	0.56	4–6	5.73	1.01	4–7
ADHD symptom severityb	29.63	9.62	9–44	23.64	8.42	9–35	21.40	7.73	10–39
Age of diagnosis (y)	29.63	5.02	22–39	8.85	3.60	3–14	29.06	5.25	24–39⁎
Age of first stimulant exposure (y)	–	–	–	9.92	2.99	4–14	28.64	5.22	23–39⁎⁎
Treatment duration (m)	–	–	–	90.92	59.74	18–228	14.62	34.95	4–120⁎⁎
Time since last stimulant exposure (m)	–	–	–	96.04	52.13	0–168	0.77	1.73	0–6⁎⁎

SD = standard deviation.

y = years.

m = months.

^aVerhage (1964).

^bKooij et al. (2005).

^⁎p < 0.05 for EST versus STN and LST subjects.

^⁎⁎p < 0.05 for EST versus LST subjects.