Table 1.
Characteristics of Korean adolescents included in the analysis
| Variable | Total | Depressive symptom |
p-value | Anxiety |
p-value | Suicidal ideation |
p-value | ||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| No | Yes | No | Yes | No | Yes | ||||||
| Total | 46,475 (100) | 35,224 (75.8) | 11,251 (24.2) | 41,562 (89.4) | 4,913 (10.6) | 41,686 (89.7) | 4,789 (10.3) | ||||
| Sleep duration | <0.001 | <0.001 | <0.001 | ||||||||
| ≥8 h | 8,086 (17.4) | 6,743 (83.4) | 1,343 (16.6) | 7,597 (94.0) | 489 (6.0) | 7,512 (92.9) | 574 (7.1) | ||||
| ≥6 h and <8 h | 19,905 (42.8) | 15,633 (78.5) | 4,272 (21.5) | 18,142 (91.1) | 1,763 (8.9) | 18,146 (91.2) | 1,759 (8.8) | ||||
| <6 h | 18,484 (39.8) | 12,848 (69.5) | 5,636 (30.5) | 15,823 (85.6) | 2,661 (14.4) | 16,028 (86.7) | 2,456 (13.3) | ||||
| Sleep satisfaction | <0.001 | <0.001 | <0.001 | ||||||||
| Sufficient | 14,321 (30.8) | 12,196 (85.2) | 2,125 (14.8) | 13,658 (95.4) | 663 (4.6) | 13,538 (94.5) | 783 (5.5) | ||||
| Just enough | 16,015 (34.5) | 12,439 (77.7) | 3,576 (22.3) | 14,637 (91.4) | 1,378 (8.6) | 14,504 (90.6) | 1,511 (9.4) | ||||
| Not enough | 16,139 (34.7) | 10,589 (65.6) | 5,550 (34.4) | 13,267 (82.2) | 2,872 (17.8) | 13,644 (84.5) | 2,495 (15.5) | ||||
| Sex | <0.001 | <0.001 | <0.001 | ||||||||
| Male | 24,157 (52.0) | 19,518 (80.8) | 4,639 (19.2) | 22,373 (92.6) | 1,784 (7.4) | 22,334 (92.5) | 1,823 (7.5) | ||||
| Female | 22,318 (48.0) | 15,706 (70.4) | 6,612 (29.6) | 19,189 (86.0) | 3,129 (14.0) | 19,352 (86.7) | 2,966 (13.3) | ||||
| School | <0.001 | <0.001 | 0.061 | ||||||||
| Middle school (7–9) | 24,144 (52.0) | 18,777 (77.8) | 5,367 (22.2) | 21,759 (90.3) | 2,349 (9.7) | 21,718 (90.0) | 2,426 (10.0) | ||||
| High school (10–12) | 22,331 (48.0) | 16,447 (73.7) | 5,884 (26.3) | 19,767 (88.5) | 2,564 (11.5) | 19,968 (89.4) | 2,363 (10.6) | ||||
| Residential area | 0.001 | <0.001 | 0.013 | ||||||||
| Metropolitan | 23,075 (49.7) | 17,661 (76.5) | 5,414 (23.5) | 20,782 (90.1) | 2,293 (9.9) | 20,793 (90.1) | 2,282 (9.9) | ||||
| Urban | 20,496 (44.0) | 15,375 (75) | 5,121 (25) | 18,207 (88.8) | 2,289 (11.2) | 18,307 (89.3) | 2,189 (10.7) | ||||
| Rural | 2,904 (6.3) | 2,188 (75.3) | 716 (24.7) | 2,573 (88.6) | 331 (11.4) | 2,586 (89.1) | 318 (10.9) | ||||
| Subjective household economic status | <0.001 | <0.001 | <0.001 | ||||||||
| High | 18,154 (39.1) | 14,110 (77.7) | 4,044 (22.3) | 16,511 (91.0) | 1,643 (9.0) | 16,554 (91.2) | 1,600 (8.8) | ||||
| Middle | 22,315 (48) | 17,129 (76.8) | 5,186 (23.2) | 20,087 (90.0) | 2,228 (10.0) | 20,184 (90.5) | 2,131 (9.5) | ||||
| Low | 6,006 (12.9) | 3,985 (66.4) | 2,021 (33.6) | 4,964 (82.7) | 1,042 (17.3) | 4,948 (82.4) | 1,058 (17.6) | ||||
| Co-residence with parents | <0.001 | 0.036 | <0.001 | ||||||||
| Yes | 44,254 (95.2) | 33,640 (76.0) | 10,614 (24.0) | 39,606 (89.5) | 4,648 (10.5) | 39,758 (89.8) | 4,496 (10.2) | ||||
| No | 2,221 (4.78) | 1,584 (71.3) | 637 (28.7) | 1,956 (88.1) | 265 (11.9) | 1,928 (86.8) | 293 (13.2) | ||||
| Subjective academic performance | <0.001 | <0.001 | <0.001 | ||||||||
| High | 17,413 (37.5) | 13,734 (78.9) | 3,679 (21.1) | 15,785 (90.7) | 1,628 (9.3) | 15,822 (90.9) | 1,591 (9.1) | ||||
| Middle | 14,131 (30.4) | 10,921 (77.3) | 3,421 (22.7) | 12,829 (90.8) | 1,302 (9.2) | 12,871 (91.1) | 1,260 (8.9) | ||||
| Low | 14,931 (32.1) | 10,569 (70.8) | 4,362 (29.2) | 12,948 (86.7) | 1,983 (13.3) | 12,993 (87.0) | 1,938 (13.0) | ||||
| Subjective health status | <0.001 | <0.001 | <0.001 | ||||||||
| Good | 32,815 (70.6) | 26,166 (79.7) | 6,649 (20.3) | 30,472 (92.9) | 2,343 (7.1) | 30,321 (92.4) | 2,494 (7.6) | ||||
| Normal | 10,317 (22.2) | 7,163 (69.4) | 3,154 (30.6) | 8,733 (84.7) | 1,584 (15.3) | 8,891 (86.2) | 1,426 (13.8) | ||||
| Bad | 3,343 (7.2) | 1,895 (56.7) | 1,448 (43.3) | 2,357 (70.5) | 986 (29.5) | 2,474 (74.0) | 869 (26.0) | ||||
| Alcohol consumption | <0.001 | <0.001 | <0.001 | ||||||||
| No | 41,801 (89.9) | 32,312 (77.3) | 9,489 (22.7) | 37,619 (90.0) | 4,182 (10.0) | 37,844 (90.5) | 3,957 (9.5) | ||||
| Yes | 4,674 (10.1) | 2,912 (62.3) | 1,762 (37.7) | 3,943 (84.4) | 731 (15.6) | 3,842 (82.2) | 832 (17.8) | ||||
| Smoking status | <0.001 | <0.001 | <0.001 | ||||||||
| No | 44,640 (96.1) | 34,145 (76.5) | 10,495 (23.5) | 34,145 (76.5) | 10,495 (23.5) | 34,145 (76.5) | 10,495 (23.5) | ||||
| Yes | 1,835 (3.9) | 1,079 (58.8) | 756 (41.2) | 1,079 (58.8) | 756 (41.2) | 1,079 (58.8) | 756 (41.2) | ||||
Values are presented as N (%)