Table 1.
Characteristics of the study samples.
| ADHD (N = 19) | Control (N = 16) | t | p | |||
|---|---|---|---|---|---|---|
| Mean (SD) | Range | Mean (SD) | Range | |||
| Age | 24.7 (5.3) | 18–36 | 26.3 (3.0) | 19–30 | 1.13 | 0.27 |
| ADHD-RS | 14.5 (6.8) | 6–27 | 0.8 (1.5) | 0–5 | 7.67 | < 0.001* |
| Alcohol | 0.4 (0.6) | 0–2 | 0.5 (0.8) | 0–3 | 0.45 | 0.65 |
| Caffeine | 2.3 (0.9) | 0–3 | 2.2 (0.8) | 1–3 | 0.26 | 0.80 |
| Smokers (%) | 40.0 | 18.8 | χ2 = 1.70 | 0.25 | ||
| Total sleep time (min.) | 423.1 (47.7) | 332.2–501.2 | 426.0 (49.9) | 335.6–519.8 | 0.16 | 0.87 |
| Sleep onset latency (min.) | 27.8 (33.7) | 2.0–100.0 | 19.3 (12.8) | 4.1–41.0 | 0.96 | 0.35 |
| Sleep efficiency (%) | 91.5 (8.2) | 66.4–99.7 | 96.2 (4.4) | 82.7–99.7 | 1.95 | 0.06 |
| WASO (min.) | 25.8 (19.4) | 1.4–62.9 | 15.0 (17.4) | 1.5–68.0 | 1.61 | 0.12 |
| Global PSQI score | 6.0 (3.0) | 1–11 | 4.4 (2.9) | 0–11 | 1.52 | 0.14 |
| PSQI > 5 (%) | 52.9 | 31.3 | χ2 = 1.59 | 0.30 | ||
Demographic characteristics and subjective measures of the participants’ sleep prior to the experimental session. SD Standard deviation, ADHD-RS ADHD Rating Scale, Alcohol number of alcoholic beverages per week, Caffeine number of caffeinated beverages per day, WASO wake after sleep onset, PSQI Pittsburgh Sleep Quality Index. Differences between the groups in the demographic variables and the pre-experimental sleep measures were examined using two-tailed independent-samples t-tests or chi-squared tests. As multiple t-test comparisons were performed, significance (*p < 0.05) was determined following the Bonferroni correction.