Characteristics of the study population
Table 2 shows the general characteristics of the participants (N = 57,925) by group: healthy group (n = 48,573; 83.9%), suicide-ideation group (n = 4,003; 6.9%), suicide-planning group (n = 1,251; 2.2%), and suicide-attempt group (n = 1,121; 1.9%).
The healthy group had more males (53.5%) than females, had a similar ratio of high school (49.9%) students to middle school students (50.1%), and featured the highest percentage of students with high academic achievement (37.4%). Many of the students in this group had parents with college or higher education levels (father 42.9%, mother 42.0%). Meanwhile, 96.4% lived with family members, while 48.0% were middle class. Next, 5.2% stated that they had experienced severe financial hardship as a result of COVID-19, while 91.1% stated that their families had not received any financial assistance. Finally, 34.2% reported average sleep adequacy, 10.0% were smokers, 31.6% were alcohol users, 0.5% had experience of drugs, and 23.7% had smartphone overdependence.
The suicide-ideation group comprised mostly females (60.4%), a higher percentage of high school students (54.3%) than middle school students, and students with poor academic achievement (39.4%). Many of the students had parents with college or higher education levels. Meanwhile, 95.2% lived with family members, while 45.2% were middle class. Next, 8.8% stated that they had experienced severe financial hardship as a result of COVID-19, while 86.6% stated that their families had not received any financial assistance. Finally, 52.1% reported inadequate sleep, 16.9% were smokers, 46.2% were alcohol users, 1.9% had experience of drugs, and 40.2% had smartphone overdependence.
The suicide-planning group comprised mostly females (55.8%), a higher percentage of middle school students (51.8%) than high school students, and students with poor academic achievement (41.2%). Many of the students had parents with college or higher education levels. Meanwhile, 94.6% lived with family members, while 44.0% were middle class. Next, 10.7% stated that they had experienced severe financial hardship as a result of COVID-19, while 84.6% stated that their families had not received any financial assistance. Finally, 53.8% reported inadequate sleep, 18.0% were smokers, 45.4% were alcohol users, 2.3% had experience of drugs, and 36.8% had smartphone overdependence.
The suicide-attempt group was predominantly female (65.4%), had a similar ratio of high school (49.3%) and middle school students (50.7%), and was the group with the highest percentage of students with poor academic achievement (47.3%). The percentage of students whose fathers were college graduates (40.6%) was similar to the percentage of students who did not know their father’s education level (41.1%). Most students’ mothers had college or higher education levels. Meanwhile, 91.0% lived with family members, while 39.7% were middle class. Next, 14.7% stated that they had experienced severe financial hardship as a result of COVID-19, while 84.6% stated that their families had not received any financial assistance. Finally, 56.0% reported inadequate sleep, 30.9% were smokers, 56.5% were alcohol users, 6.6% had experience of drugs, and 36.2% had smartphone overdependence.
Table 2
Characteristics of the study population
Variables
|
Healthy
adolescents
(N = 48,573)
|
Suicide-ideation adolescents
(N = 4,003)
|
Suicide-plan
adolescents
(N = 1,251)
|
Suicide-attempt adolescents
(N = 1,121)
|
χ2
p
|
no.
|
Weighted
no.
|
Weighted %
|
no.
|
Weighted
no.
|
Weighted %
|
no.
|
Weighted
no.
|
Weighted %
|
no.
|
Weighted
no.
|
Weighted %
|
Sex
|
Male
|
25,880
|
1,244,439
|
53.5
|
1,552
|
75,593
|
39.6
|
539
|
26,365
|
44.2
|
382
|
18,443
|
34.6
|
452.84
|
|
Female
|
22,693
|
1,083,465
|
46.5
|
2,451
|
115,455
|
60.4
|
712
|
33,303
|
55.8
|
739
|
34,825
|
65.4
|
***
|
Education level
|
Middle
|
25,699
|
1,160,962
|
49.9
|
1,980
|
87,276
|
45.7
|
690
|
30,881
|
51.8
|
592
|
26,247
|
49.3
|
28.28
|
High
|
22,874
|
1,166,942
|
50.1
|
2,023
|
103,772
|
54.3
|
561
|
28,787
|
48.2
|
529
|
27,021
|
50.7
|
***
|
Academic achievement
|
Poor
|
15,567
|
743,845
|
32.0
|
1,598
|
75,191
|
39.4
|
521
|
24,555
|
41.2
|
531
|
25,215
|
47.3
|
239.89
|
Middle
|
14,916
|
713,371
|
30.6
|
1,059
|
50,541
|
26.5
|
339
|
16,152
|
27.1
|
271
|
12,896
|
24.2
|
***
|
High
|
18,090
|
870,688
|
37.4
|
1,346
|
65,316
|
34.2
|
391
|
18,961
|
31.8
|
319
|
15,157
|
28.5
|
|
Father
education
level
|
Under high school
|
8,853
|
401,796
|
17.3
|
786
|
35,023
|
18.3
|
225
|
10,241
|
17.2
|
213
|
9,738
|
18.3
|
9.77
|
College or higher
|
20,023
|
997,547
|
42.9
|
1,685
|
83,770
|
43.8
|
509
|
25,588
|
42.9
|
421
|
21,623
|
40.6
|
|
Unknown
|
19,697
|
928,561
|
39.9
|
1,532
|
72,255
|
37.8
|
517
|
23,839
|
40.0
|
487
|
21,908
|
41.1
|
|
Mother
education
level
|
Under high school
|
10,166
|
46,541
|
2.0
|
962
|
44,336
|
23.2
|
266
|
12,279
|
20.6
|
262
|
12,792
|
24.0
|
33.88
|
College or higher
|
19,695
|
976,940
|
42.0
|
1,608
|
78,578
|
41.1
|
481
|
23,833
|
39.9
|
423
|
20,549
|
38.6
|
***
|
Unknown
|
18,712
|
881,423
|
37.9
|
1,433
|
68,134
|
35.7
|
504
|
23,556
|
39.5
|
436
|
19,927
|
37.4
|
|
Living
arrangement
|
With family
|
46,379
|
2,244,820
|
96.4
|
3,772
|
181,951
|
95.2
|
1,170
|
56,445
|
94.6
|
1,011
|
48,463
|
91.0
|
108.63
|
Without Family
|
2,194
|
83,084
|
3.6
|
231
|
9,097
|
4.8
|
81
|
3,223
|
5.4
|
110
|
4,805
|
9.0
|
***
|
Economic status
|
Low
|
5,810
|
268,411
|
11.5
|
837
|
38,224
|
20.0
|
273
|
12,013
|
20.1
|
292
|
13,077
|
24.5
|
464.42
|
Middle
|
23,582
|
1,116,796
|
48.0
|
1,812
|
86,389
|
45.2
|
556
|
26,273
|
44.0
|
447
|
21,166
|
39.7
|
***
|
High
|
19,181
|
942,697
|
40.5
|
1,354
|
66,436
|
34.8
|
422
|
21,383
|
35.8
|
382
|
19,025
|
35.7
|
|
Economic status changed due to COVID-19
|
Not at all
|
14,767
|
718,326
|
30.9
|
940
|
46,767
|
24.5
|
305
|
14,820
|
24.8
|
256
|
12,535
|
23.5
|
479.25
|
Really
|
19,518
|
939,020
|
40.3
|
1,536
|
73,861
|
38.7
|
430
|
20,294
|
34.0
|
357
|
16,852
|
31.6
|
***
|
Changed
|
11,698
|
549,901
|
23.6
|
1,163
|
53,584
|
28.0
|
389
|
18,160
|
30.4
|
333
|
16,050
|
30.1
|
|
Critically
|
2,590
|
120,658
|
5.2
|
364
|
16,837
|
8.8
|
127
|
6,394
|
10.7
|
175
|
7,831
|
14.7
|
|
Financial
assistance
|
No
|
43,961
|
2,121,168
|
91.1
|
3,437
|
165,410
|
86.6
|
1,053
|
50,486
|
84.6
|
934
|
45,084
|
84.6
|
187.87
|
Yes
|
4,612
|
206,736
|
8.9
|
566
|
25,638
|
13.4
|
198
|
9,182
|
15.4
|
187
|
8,184
|
15.4
|
***
|
Sleep
|
Adequate
|
15,721
|
745,642
|
32.0
|
671
|
31,280
|
16.4
|
244
|
11,509
|
19.3
|
188
|
9,115
|
17.1
|
1046.14
|
average
|
16,750
|
795,703
|
34.2
|
1,260
|
60,185
|
31.5
|
344
|
16,039
|
26.9
|
302
|
14,316
|
26.9
|
***
|
Inadequate
|
16,102
|
786,559
|
33.8
|
2,072
|
99,582
|
52.1
|
663
|
32,121
|
53.8
|
631
|
29,837
|
56.0
|
|
Smoking
|
No
|
43,766
|
2,096,121
|
90.0
|
3,308
|
158,675
|
83.1
|
1,024
|
48,923
|
82.0
|
769
|
36,822
|
69.1
|
705.07
|
Yes
|
4,807
|
231,783
|
10.0
|
695
|
32,373
|
16.9
|
227
|
10,745
|
18.0
|
352
|
16,447
|
30.9
|
***
|
Drinking
|
No
|
33,285
|
1,593,087
|
68.4
|
2,144
|
102,850
|
53.8
|
687
|
32,578
|
54.6
|
475
|
23,150
|
43.5
|
713.53
|
Yes
|
15,288
|
734,817
|
31.6
|
1,859
|
88,198
|
46.2
|
564
|
27,090
|
45.4
|
646
|
30,118
|
56.5
|
***
|
Drug use
|
No
|
48,346
|
2,316,576
|
99.5
|
3,931
|
187,475
|
98.1
|
1,226
|
58,300
|
97.7
|
1,040
|
49,752
|
93.4
|
662.34
|
Yes
|
227
|
11,328
|
0.5
|
72
|
3,573
|
1.9
|
25
|
1,368
|
2.3
|
81
|
3,516
|
6.6
|
***
|
Smartphone
overdependence
|
No
|
37,209
|
1,776,021
|
76.3
|
2,434
|
114,313
|
59.8
|
809
|
37,702
|
63.2
|
721
|
33,990
|
63.8
|
685.41
|
Yes
|
11,364
|
551,883
|
23.7
|
1,569
|
76,735
|
40.2
|
442
|
21,966
|
36.8
|
400
|
19,278
|
36.2
|
***
|
* <0.05, ** <0.01, *** <0.001 |
Comparisons of stress, sadness and despair, loneliness, and GAD among the different groups of adolescents
Comparisons of the key variables are displayed in Fig. 1.
The suicide-attempt group showed the highest level of stress (4.136); this group was followed by the suicide-ideation group (3.938), suicide-planning group (3.923), and healthy group (3.065), respectively. The difference was statistically significant (p < .0001).
The suicide-attempt group showed the highest level of sadness and despair (1.807); this group was followed by the suicide-ideation group (1.684), suicide-planning group (1.680), and healthy group (1.192), respectively. The difference was statistically significant (p < .0001).
The suicide-attempt group showed the highest level of loneliness (3.645); this group was followed by the suicide-ideation group (3.331), suicide-planning group (3.305), and healthy group (2.281), respectively. The difference was statistically significant (p < .0001).
The suicide-attempt group showed the highest level of GAD (10.252); this group was followed by the suicide-planning group (8.685), suicide-ideation group (8.131), and healthy group (3.289), respectively. The difference was statistically significant (p < .0001).
Predictors of mental health status among Korean adolescents
Table 3 shows the results of the multiple logistic regression analysis that was performed to identify the predictors of mental health status among Korean adolescents.
The odds ratios (ORs) for stress, sadness and despair, loneliness, and GAD were higher among males than females (stress OR = 1.779, 95% CI = 1.700-1.862; sadness and despair OR = 1.632, 95% CI = 1.561–1.707; loneliness OR = 1.768, 95% CI = 1.703–1.836 and GAD OR = 1.581, 95% CI = 1.517–1.646). Regarding education level, the ORs for stress (OR = 1.113, 95% CI = 1.063–1.166) and GAD (OR = 1.071, 95% CI = 1.027–1.116) were higher among high schoolers than middle schoolers. Regarding academic achievement, the ORs were lower among students with good grades than those with poor grades (stress in high ORs = 0.901, 95% CI = 0.852–0.953; sadness and despair in middle ORs = 0.843, 95% CI = 0.799–0.890; in high ORs = 0.770, 95% CI = 0.729–0.813; loneliness in middle ORs = 0.893, 95% CI = 0.853–0.936; in high ORs = 0.940, 95% CI = 0.897–0.984; and GAD in middle ORs = 0.908, 95% CI = 0.863–0.954; in high ORs = 0.937, 95% CI = 0.892–0.985). The ORs for stress, sadness and despair, and loneliness were higher among students whose fathers were college graduates than among those whose fathers had high school or lower education levels (stress in college or higher ORs = 1.134, 95% CI = 1.055–0.128; in unknown ORs = 1.094, 95% CI = 1.005–1.191; sadness and despair in college or higher ORs = 1.086, 95% CI = 1.013–1.164; loneliness in college or higher ORs = 1.073, 95% CI = 1.011–1.139). The ORs for GAD was lower among students whose mothers were unknown than among those whose mothers had below high school education (ORs = 0.928, 95% CI = 0.862–0.999). Regarding living arrangement, the ORs for loneliness was higher among students who lived with a non-family member than those who lived with a family member (ORs = 1.182, 95% CI = 1.084–1.290). Regarding economic status, the ORs were lower among students with middle and high status than those with low status (stress in middle ORs = 0.781, 95% CI = 0.721–0.847; in high ORs = 0.704, 95% CI = 0.647–0.766; sadness and despair in middle ORs = 0.857, 95% CI = 0.801–0.917; loneliness in middle ORs = 0.754, 95% CI = 0.709–0.801; in high ORs = 0.715, 95% CI = 0.669–0.764; and GAD in middle ORs = 0.767, 95% CI = 0.721–0.817; in high ORs = 0.743, 95% CI = 0.693–0.795). The ORs were higher among those who had experienced financial hardship as a result of COVID-19 than among those who did not experience such financial difficulty (stress in really ORs = 1.310, 95% CI = 1.245–1.379; in changed ORs = 1.507, 95% CI = 1.418–1.603; in critically ORs = 1.540, 95% CI = 1.382–1.715; sadness and despair in really ORs = 1.068, 95% CI = 1.011–1.128; in changed ORs = 1.294, 95% CI = 1.218–1.376; in critically ORs = 1.645, 95% CI = 1.497–1.808; loneliness in really ORs = 1.336, 95% CI = 1.277–1.398; in changed ORs = 1.585, 95% CI = 1.505–1.669; in critically ORs = 1.536, 95% CI = 1.409–1.674 and GAD in really ORs = 1.196, 95% CI = 1.137–1.1257; in changed ORs = 1.382, 95% CI = 1.307–1.462; in critically ORs = 1.500, 95% CI = 1.370–1.641). Regarding financial assistance, the ORs for sadness and despair, loneliness, and GAD were higher among students who lived with a non-family member than those who lived with a family member (sadness and despair ORs = 1.147, 95% CI = 1.068–1.1233; loneliness ORs = 1.133, 95% CI = 1.062–1.208; GAD ORs = 1.115, 95% CI = 1.402–1.193). The ORs were higher among those who had adequate sleep than among those who had not experienced adequate sleep (stress in average ORs = 2.242, 95% CI = 2.133–2.358; in inadequate ORs = 3.197, 95% CI = 3.024–3.381; sadness and despair in average ORs = 1.399, 95% CI = 1.320–1.483; in inadequate ORs = 2.132, 95% CI = 2.016–2.255; loneliness in average ORs = 1.666, 95% CI = 1.592–1.743; in inadequate ORs = 2.206, 95% CI = 2.107–2.311; and GAD in average ORs = 1.639, 95% CI = 1.555–1.728; in inadequate ORs = 2.759, 95% CI = 2.621–2.905). The values for sadness and despair (ORs = 1.405, 95% CI = 1.310–1.507) and for loneliness(ORs = 1.256, 95% CI = 1.176–1.340) were higher among smokers than non-smokers. The ORs for all four mental health conditions were higher among those with inadequate sleep, alcohol users, drug users, and individuals with smartphone overdependence.
Table 3
Multiple logistic regression analysis on stress, sadness and despair, loneliness, and generalized anxiety disorder of 54,948 students
Variables
|
Stress
|
Sadness and despair
|
Loneliness
|
GAD
|
ORs
|
p
|
ORs
|
p
|
ORs
|
p
|
ORs
|
p
|
(95%
|
CI)
|
(95%
|
CI)
|
(95%
|
CI)
|
(95%
|
CI)
|
Sex
(Ref.=Male)
|
Female
|
1.779
|
***
|
1.632
|
***
|
1.768
|
***
|
1.581
|
***
|
1.700
|
1.862
|
1.561
|
1.707
|
1.703
|
1.836
|
1.517
|
1.646
|
Education level
(Ref.= Middle)
|
High
|
1.113
|
***
|
0.999
|
|
1.002
|
|
1.071
|
**
|
1.063
|
1.166
|
0.955
|
1.046
|
0.964
|
1.041
|
1.027
|
1.116
|
Academic achievement
(Ref.=Poor)
|
Middle
|
0.989
|
|
0.843
|
***
|
0.893
|
***
|
0.908
|
***
|
0.935
|
1.046
|
0.799
|
0.890
|
0.853
|
0.936
|
0.863
|
0.954
|
High
|
0.901
|
***
|
0.770
|
***
|
0.940
|
**
|
0.937
|
*
|
0.852
|
0.953
|
0.729
|
0.813
|
0.897
|
0.984
|
0.892
|
0.985
|
Father education
level
(Ref.= Below high school)
|
College or higher
|
1.134
|
**
|
1.086
|
*
|
1.073
|
*
|
1.060
|
|
1.055
|
1.218
|
1.013
|
1.164
|
1.011
|
1.139
|
0.995
|
1.130
|
Unknown
|
1.094
|
*
|
1.037
|
|
0.961
|
|
1.005
|
|
1.005
|
1.191
|
0.956
|
1.125
|
0.896
|
1.031
|
0.932
|
1.083
|
Mother education
level
(Ref.= Below high school)
|
College or higher
|
0.975
|
|
1.034
|
|
1.002
|
|
1.019
|
|
0.910
|
1.045
|
0.968
|
1.105
|
0.947
|
1.061
|
0.959
|
1.083
|
Unknown
|
0.979
|
|
1.010
|
|
0.953
|
|
0.928
|
*
|
0.900
|
1.065
|
0.933
|
1.094
|
0.889
|
1.020
|
0.862
|
0.999
|
Living arrangement
(Ref.=With family)
|
Without family
|
0.976
|
|
1.012
|
|
1.182
|
***
|
0.986
|
|
0.877
|
1.086
|
0.916
|
1.117
|
1.084
|
1.290
|
0.899
|
1.082
|
Economic status
(Ref.=Low)
|
Middle
|
0.781
|
***
|
0.857
|
***
|
0.754
|
***
|
0.767
|
***
|
0.721
|
0.847
|
0.801
|
0.917
|
0.709
|
0.801
|
0.721
|
0.817
|
High
|
0.704
|
***
|
0.937
|
|
0.715
|
***
|
0.743
|
***
|
0.647
|
0.766
|
0.870
|
1.009
|
0.669
|
0.764
|
0.693
|
0.795
|
Economic status changed due to COVID-19
(Ref.=Not at all)
|
Really
|
1.310
|
***
|
1.068
|
*
|
1.336
|
***
|
1.196
|
***
|
1.245
|
1.379
|
1.011
|
1.128
|
1.277
|
1.398
|
1.137
|
1.257
|
Changed
|
1.507
|
***
|
1.294
|
***
|
1.585
|
***
|
1.382
|
***
|
1.418
|
1.603
|
1.218
|
1.376
|
1.505
|
1.669
|
1.307
|
1.462
|
Critically
|
1.540
|
***
|
1.645
|
***
|
1.536
|
***
|
1.500
|
***
|
1.382
|
1.715
|
1.497
|
1.808
|
1.409
|
1.674
|
1.370
|
1.641
|
Financial assistance
(Ref.=No)
|
Yes
|
1.005
|
|
1.147
|
***
|
1.133
|
***
|
1.115
|
**
|
0.927
|
1.089
|
1.068
|
1.233
|
1.062
|
1.208
|
1.042
|
1.193
|
Sleep
(Ref.=Adequate)
|
Average
|
2.242
|
***
|
1.399
|
***
|
1.666
|
***
|
1.639
|
***
|
2.133
|
2.358
|
1.320
|
1.483
|
1.592
|
1.743
|
1.555
|
1.728
|
Inadequate
|
3.197
|
***
|
2.132
|
***
|
2.206
|
***
|
2.759
|
***
|
3.024
|
3.381
|
2.016
|
2.255
|
2.107
|
2.311
|
2.621
|
2.905
|
Smoking
(Ref.=No)
|
Yes
|
0.945
|
|
1.405
|
***
|
1.256
|
***
|
1.029
|
|
0.872
|
1.024
|
1.310
|
1.507
|
1.176
|
1.340
|
0.961
|
1.101
|
Drinking
(Ref.=No)
|
Yes
|
1.148
|
***
|
1.396
|
***
|
1.373
|
***
|
1.166
|
***
|
1.089
|
1.210
|
1.329
|
1.467
|
1.315
|
1.433
|
1.114
|
1.221
|
Drug use
(Ref.=No)
|
Yes
|
1.510
|
*
|
2.216
|
***
|
1.397
|
**
|
2.056
|
***
|
1.072
|
2.127
|
1.742
|
2.820
|
1.096
|
1.781
|
1.621
|
2.608
|
Smartphone
overdependence
(Ref.=No)
|
Yes
|
1.724
|
***
|
1.484
|
***
|
1.817
|
***
|
2.436
|
***
|
1.627
|
1.828
|
1.415
|
1.556
|
1.741
|
1.897
|
2.333
|
2.545
|
Suicide
(Ref.=Healthy)
|
Ideation
|
6.233
|
***
|
7.080
|
***
|
4.950
|
***
|
5.227
|
***
|
5.237
|
7.417
|
6.581
|
7.616
|
4.528
|
5.411
|
4.844
|
5.640
|
Plan
|
3.211
|
***
|
7.144
|
***
|
3.595
|
***
|
5.293
|
***
|
2.563
|
4.022
|
6.300
|
8.101
|
3.121
|
4.142
|
4.641
|
6.037
|
Attempt
|
6.003
|
***
|
11.911
|
***
|
6.136
|
***
|
6.602
|
***
|
4.320
|
8.343
|
10.191
|
13.921
|
5.098
|
7.384
|
5.678
|
7.676
|
GAD: Generalized anxiety disorder |
* <0.05, ** <0.01, *** <0.001 |