Table 1.
Mean values (and standard deviation) and within-subject effect sizes for demographic, sleep, and depressed mood characteristics of the school-based sample
| Predictor variable | Time 1 | Time 2 | Within-subject effect sizesa | |
|---|---|---|---|---|
| Age | 15.69 (0.92) | 16.48 (0.94)** | –0.85 | |
| Sex (male) | 89 (64%) | 89 (64%) | 0.00 | |
| CES-D | 11.88 (9.50) | 18.44 (13.94)** | –0.55 | |
| SOL (minutes) | School | 34.35 (31.48) | 27.81 (27.98)** | 0.22 |
| Weekend | 24.36 (24.87) | 17.82 (16.54)** | 0.31 | |
| TST (hours) | School | 8.19 (1.18) | 7.99 (1.11)* | 0.17 |
| Weekend | 9.35 (1.54) | 9.19 (1.08) | 0.12 | |
| WASO (minutes) | School | 9.76 (22.15) | 14.81 (32.85) | –0.18 |
| Weekend | 9.74 (20.64) | 19.83 (37.56) | –0.33 |
Notes:
a
Effect sizes were calculated using Cohen’s d.
**
,≤0.001;
*
,≤0.05.
Abbreviations: CES-D, Centre for Epidemiologic Studies Depression Scale; SOL, sleep onset latency; TST, total sleep time; WASO, wake after sleep onset.