Table 1.
Overview of three cohorts of children and adolescents with ADHD included in the primary analyses.
| ABCD | NCR | NKI-Rockland | |
|---|---|---|---|
| N ADHD | 1518 | 154 | 47 |
| Design | Large (21 sites) developmental longitudinal cohort approximating the diversity of the United States population on sex, race/ethnicity, and socioeconomic status. | Clinical cohort using accelerated longitudinal design. | Community sample based in Rockland County (15 miles northwest of New York City). |
| Mean age at baseline (sd) | 9.89 (0.62) | 8.76 (2.28) | 9.47 (2.23) |
| Mean age at final follow-up (sd) | 11.97 (0.66) | 14.64 (2.29) | 11.67 (2.24) |
| Age range | >9, <13 years | >4, <18 years | >6, <18 years |
| Median duration between assessments (IQR) | 1 years (0) | 1.46 years (1.09) | 1.1 years (0.29) |
| N assessments | 3 | Range 3–9, median = 4 (IQR = 2) | 3 |
| Sex (%) | |||
| Male | 1023 (67.4%) | 105 (68.2%) | 35 (74.5%) |
| Female | 495 (32.6%) | 49 (31.83%) | 12 (25.5%) |
| Race (%) | |||
| Black/African American | 218 (14.4%) | 20 (13%) | 10 (21.3%) |
| More than one race/declined/other | 315 (20.8%) | 24 (15.5%) | 6 (12.8%) |
| White | 985 (64.9%) | 110 (71.4%) | 31 (66%) |
| Ethnicity (%) | |||
| Non-Hispanic | 1244 (83.3%) | 140 (90.3%) | 35 (74.5%) |
| Hispanic | 249 (16.7%) | 15 (9.7%) | 12 (25.5%) |
Abbreviations. ABCD, Adolescent Brain Cognitive Development Study; IQR, Interquartile range; NCR, Neurobehavioral Clinical Research; NKI-Rockland, Enhanced Nathan Kline Institute-Rockland.
Missing data ABCD: N = 25 missing ethnicity.