Table 7.

Prevalence ranges for ADHD/ADD-H according to DSM diagnostic criteria for US and non-US populations

		N	Approximate range for mean age (years)	Prevalence range
DSM-III
	US studies	4	9-11	9.1-12 (n = 3)
	non-US studies	7	7-11	5.8-11.2 (n = 6)
DSM-III-R
	US studies	6	8-12	7.1-12.8 (n = 4)
	non-US studies	9	6-11	3.9-10.9 (n = 7)
DSM-IV
	US studies	4	8-10	11.4-16.1 (n = 4)
	non-US studies	9	7.5-11	16-19.8 (n = 5) (higher prevalence studies)
				2.4-7.5 (n = 4) (lower prevalence studies)