Table 2.
Factors associated with depressive symptoms and suicidal behaviors.
| Variables | Depressive symptoms | Suicidal ideation | ||||||
|---|---|---|---|---|---|---|---|---|
| Male | Female | Male | Female | |||||
| aOR | 95% CI | aOR | 95% CI | aOR | 95% CI | aOR | 95% CI | |
| Weekend catch-up sleep ratioa | ||||||||
| CUS < 1.00 | 1.05 | (1.00–1.11) | 1.10 | (1.04–1.16) | 1.11 | (1.08–1.22) | 1.15 | (1.08–1.23) |
| 1.00 ≤ CUS < 1.50 | 1.00 | 1.00 | 1.00 | 1.00 | ||||
| CUS ≥ 1.50 | 1.02 | (0.98–1.06) | 1.04 | (1.01–1.08) | 0.97 | (0.91–1.02) | 1.02 | (0.98–1.06) |
| Subjective sleep quality | ||||||||
| Poor | 1.48 | (1.41–1.55) | 1.35 | (1.29–1.41) | 1.39 | (1.30–1.48) | 1.25 | (1.18–1.33) |
| Moderate | 1.22 | (1.17–1.28) | 1.10 | (1.05–1.15) | 1.15 | (1.08–1.22) | 1.07 | (1.01–1.14) |
| Good | 1.00 | 1.00 | 1.00 | 1.00 | ||||
| Sleep duration (h)b | ||||||||
| Duration < 5 | 1.40 | (1.31–1.50) | 1.38 | (1.31–1.45) | 1.65 | (1.51–1.80) | 1.58 | (1.49–1.69) |
| 5 ≤ Duration < 7 | 1.17 | (1.13–1.22) | 1.13 | (1.10–1.18) | 1.23 | (1.16–1.30) | 1.20 | (1.15–1.26) |
| 7 ≤ Duration < 9 | 1.00 | 1.00 | 1.00 | 1.00 | ||||
| Duration ≥ 9 | 0.96 | (0.90–1.03) | 1.01 | (0.94–1.08) | 1.04 | (0.94–1.14) | 0.96 | (0.87–1.05) |
| School year | ||||||||
| Mid1 (Grade 7) | 1.12 | (1.04–1.19) | 1.30 | (1.23–1.38) | 1.76 | (1.60–1.94) | 2.52 | (2.34–2.72) |
| Mid2 (Grade 8) | 1.12 | (1.05–1.19) | 1.39 | (1.31–1.46) | 1.85 | (1.69–2.02) | 2.45 | (2.28–2.63) |
| Mid3 (Grade 9) | 1.22 | (1.15–1.29) | 1.38 | (1.31–1.46) | 1.78 | (1.64–1.94) | 2.17 | (2.02–2.33) |
| High1 (Grade 10) | 1.01 | (0.96–1.07) | 1.04 | (0.99–1.09) | 1.21 | (1.12–1.32) | 1.37 | (1.28–1.47) |
| High2 (Grade 11) | 1.00 | (0.95–1.05) | 1.06 | (1.01–1.12) | 1.18 | (1.09–1.27) | 1.28 | (1.20–1.36) |
| High3 (Grade 12) | 1.00 | 1.00 | 1.00 | 1.00 | ||||
| Economic status | ||||||||
| Low | 1.24 | (1.13–1.36) | 1.16 | (1.05–1.28) | 1.58 | (1.41–1.78) | 1.57 | (1.39–1.77) |
| Medium–low | 0.94 | (0.88–1.00) | 0.95 | (0.89–1.02) | 1.07 | (0.98–1.17) | 1.27 | (1.17–1.38) |
| Medium | 0.81 | (0.77–0.86) | 0.81 | (0.76–0.85) | 0.81 | (0.75–0.88) | 0.88 | (0.82–0.94) |
| Medium–high | 0.91 | (0.86–0.96) | 0.91 | (0.86–0.96) | 0.87 | (0.81–0.95) | 0.95 | (0.88–1.02) |
| High | 1.00 | 1.00 | 1.00 | 1.00 | ||||
| Residence type | ||||||||
| Live w/o family or relative | 1.00 | 1.00 | 1.00 | 1.00 | ||||
| Live with relative | 1.39 | (1.15–1.68) | 1.57 | (1.28–1.92) | 1.53 | (1.20–1.94) | 1.52 | (1.22–1.88) |
| Live with family | 0.88 | (0.82–0.96) | 0.97 | (0.90–1.05) | 0.85 | (0.77–0.94) | 0.93 | (0.85–1.03) |
| Academic achievement | ||||||||
| Low | 1.36 | (1.27–1.46) | 1.60 | (1.50–1.70) | 1.17 | (1.07–1.28) | 1.31 | (1.21–1.43) |
| Medium–low | 1.29 | (1.22–1.37) | 1.43 | (1.36–1.51) | 1.19 | (1.10–1.28) | 1.19 | (1.11–1.28) |
| Medium | 1.17 | (1.10–1.24) | 1.26 | (1.20–1.33) | 1.11 | (1.03–1.20) | 1.03 | (0.96–1.10) |
| Medium–high | 1.11 | (1.05–1.17) | 1.11 | (1.06–1.17) | 1.04 | (0.97–1.12) | 1.02 | (0.95–1.09) |
| High | 1.00 | 1.00 | 1.00 | 1.00 | ||||
| Alcohol status | ||||||||
| Ever | 1.41 | (1.36–1.46) | 1.51 | (1.46–1.56) | 1.37 | (1.30–1.43) | 1.54 | (1.48–1.61) |
| Never | 1.00 | 1.00 | 1.00 | 1.00 | ||||
| Smoking status | ||||||||
| Everyday | 1.62 | (1.52–1.73) | 1.88 | (1.69–2.11) | 1.46 | (1.34–1.58) | 1.63 | (1.45–1.83) |
| Some day | 1.27 | (1.21–1.33) | 1.48 | (1.39–1.58) | 1.28 | (1.21–1.36) | 1.53 | (1.43–1.64) |
| Never | 1.00 | 1.00 | 1.00 | 1.00 | ||||
| Physical activity | ||||||||
| Low | 0.77 | (0.75–0.80) | 0.83 | (0.80–0.85) | 0.93 | (0.89–0.97) | 0.84 | (0.80–0.87) |
| High | 1.00 | 1.00 | 1.00 | 1.00 | ||||
| Self-reported health status | ||||||||
| Low | 1.00 | 1.00 | 1.00 | 1.00 | ||||
| Medium | 0.75 | (0.70–0.81) | 0.69 | (0.65–0.73) | 0.62 | (0.57–0.67) | 0.59 | (0.56–0.63) |
| High | 0.63 | (0.59–0.67) | 0.51 | (0.48–0.53) | 0.42 | (0.39–0.46) | 0.40 | (0.37–0.42) |
| Perception of stress | ||||||||
| Low | 0.12 | (0.11–0.13) | 0.11 | (0.10–0.12) | 0.09 | (0.08–0.10) | 0.09 | (0.08–0.10) |
| Medium | 0.31 | (0.30–0.32) | 0.32 | (0.31–0.33) | 0.22 | (0.21–0.24) | 0.24 | (0.23–0.25) |
| High | 1.00 | 1.00 | 1.00 | 1.00 | ||||
aWeekend sleep duration/weekday sleep duration.
bAverage sleep duration of weekday and weekend.
aOR adjusted odds ratio, CI Confidence Interval.