| Â | CTL | ADHD | ASD (without ADHD) |
|---|
N | 59 | 15 | 57 |
Male (%) | 53% | 53% | 75% |
Age (years) |
 Mean (M) | 13.3 ± 4.6 | 15.3 ± 3.5 | 13.7 ± 4.8 |
 Median (Mdn) | 12.8 | 15.5 | 13.3 |
 Range | 5–25 | 8–20 | 6–27 |
Iris colour indexa | 1.25 ± 0.13 | 1.26 ± 0.12 | 1.20 ± 0.11 |
Vert | 2.4 ± 0.8 | 1.5 ± 1.3 | 2.2 ± 0.8 |
Ethnicity (%) |
 Caucasian | 35 (59) | 11 (73) | 47 (82) |
 Asian | 18 (31) | 2 (13) | 3 (5) |
 Afro-Caribbean | 0 | 1 (7) | 1 (2) |
 Latino | 0 | 1 (7) | 1 (2) |
 Mixed | 6 (10) | 0 | 5 (9) |
FSIQ (n) | – | 92.9 ± 14.2 (10) | 99.6 ± 18.9 (37) |
ADHD severityb(n) | – | 4.0 ± 0.9 (11) | 2.0 ± 0.8 (25) |
 Hyperactivity |  | 5.5 ± 2.3 | 2.0 ± 1.8 |
 Impulsivity |  | 4.1 ± 1.9 | 3.1 ± 1.9 |
 Inattention |  | 9.5 ± 3.4 | 6.3 ± 4.0 |
ADOS total | – | – | 11.0 ± 4.8 (34) |
ASD severity | – | – | 6.2 ± 2.0 (34) |
NMed | – | 2c | 8 |
- All data are presented as M ± SD
- CTL Control, with no ASD or ADHD proband in their first-degree family; N Number of participants; FSIQ Full Scale IQ; n Number of data collected, as some participants diagnosed in the local clinics did not have their phenotypic data; ADOS total Autism Diagnostic Observation Schedule total score (0–28, higher the score more severe); ASD severity Autism severity score (range 1–10, ≥ 4 is ASD, higher the score more severe); NMed Number of participants taking medications before testing
- aThe distribution of the iris colour index of each group is displayed in Additional file 1: Fig. S1; Vert Vertical distance (mm) of the electrode below the lower eyelid
- bADHD severity ADHD severity score (maximum is 6, higher more severe), each ADHD subset score (hyperactivity, impulsivity and inattention) was the combined score evaluated by parents/carers and schoolteachers
- cAnother five ADHD subjects had been tested before and after taking ADHD medications
