Table 1.
Demographic and Clinical Characteristics of the Participants
| Control | Psychosis | ADHD | Diagnosis Effects | Post-Hoc Tests | |
|---|---|---|---|---|---|
| N | 58 | 29 | 33 | ||
| M:F, % | 45:55 | 52:48 | 79:21 | X22 = 10.1, p = .006, φ = .29 | ADHD ≠ (Psychosis, C) |
| Age in years (SD) | 12.8 (2.8) | 14.9 (3.4) | 12.8 (2.7) | F2,117 = 5.46, p = .005, η2p = .09 | Psychosis > (ADHD = C) |
| Range | 8.8-20.1 | 8.4-20.1 | 8.8-18.9 | ||
| Parental socioeconomic statusa | 53 (10) | 42 (14) | 50 (9) | F2,108 = 9.23, p < .001 η2p = .15 | Psychosis < (ADHD = C) |
| Estimated IQb (SD) | 114 (13) | 97 (16) | 108 (14) | F2,108 = 12.69, p < .001, η2p = .19 | Psychosis < (ADHD = C) |
| Range | 77-144 | 74-132 | 85-141 | ||
| WIATc | |||||
| Reading | 110 (10) | 97 (16) | 103 (13) | F2,112 = 11.49, p < .001, η2p> = .17 | (Psychosis = ADHD) < C |
| Spelling | 109 (11) | 98 (15) | 98 (13) | F2,112 = 10.57, p < .001, η2p = .16 | (Psychosis = ADHD) < C |
| Handedness | 6.4 (1.7) | 5.5 (2.5) | 6.2 (1.8) | ns | |
| SANS/SAPSd,e | |||||
| Negative symptoms | 2.8 (1.0) | ||||
| Positive symptoms | 1.8 (1.0) | ||||
| Psychotic symptoms | 2.5 (1.2) | ||||
| Medications, % | |||||
| Antipsychotic | 17 (59%) | 0 | |||
| Psychostimulant | 4 (14%) | 20 (61%) | |||
| Antidepressant | 9 (31%) | 1 (3%) | |||
| Mood stabilizer | 8 (28%) | 0 | |||
| Alpha-adrenergic | 2 (7%) | 2 (6%) | |||
| Anti-histamine | 3 (10%) | 0 | |||
| Benzodiazepine | 3 (10%) | 0 | |||
| Ethnicity | X82 = 18.3,p = .019,ϕ = .39 | ||||
| Caucasian | 50 (86%) | 17 (59%) | 28 (85%) | ||
| African-American | 1 (2 %) | 3 (10%) | 4 (12%) | ||
| Asian | 1 (2 %) | 3 (10%) | 0 | ||
| Hispanic | 1 (3%) | 0 | |||
| Mixed/Other | 6 (10%) | 5 (17%) | 1 (3%) |
Notes. C = Control. ns = not significant. SANS/SAPS = Scales for the Assessment of Negative/Positive Symptoms. WIAT = Wechsler Individual Achievement Test. Medications taken by fewer than 5% of participants are not reported. Handedness was measured by asking children to pick up seven objects with their preferred hand; 1 point was awarded for each object picked up with the right hand.
IQ was estimated from the Vocabulary and Block Design subtests from the Wechsler Intelligence Scale, 3rd ed. (WISC-III; Wechsler, 1991), the WISC-IV (Wechsler, 2003), or the Wechsler Adult Intelligence Scale, 3rd ed. (Wechsler, 1997).
The values for the SANS and SAPS were calculated as the mean of the global measures within each instrument (O'Leary, Flaum, Kesler, Flashman, Arndt, & Andreasen, 2000).