Table 1 Demographic characteristics of all participants

Age, years

26.0 [25.0, 32.0]

30.5 [25.8, 38.2]

25.0 [23.0, 38.0]

H = 3.378, p = 0.185

Sex (F/M)

5/5

9/9

16/3

χ² = 5.616, p = 0.060

Race

χ² = 0.000, p = 1.000

 Han

10

18

19

 Non-Han

0

0

0

Place of residence

χ² = 1.233, p = 0.540

 Downtown

9

13

15

 Suburb

1

4

3

 Village

0

1

1

Marriage

χ² = 2.798, p = 0.247

 Unmarried

7

7

10

 Married

3

10

9

 Bereavement/divorce

0

1

0

Family history of insomnia (Y/N)

1/9

3/15

1/18

χ² = 1.243, p = 0.537

Family history of psychosis (Y/N)

0/10

0/18

1/18

χ² = 1.474, p = 0.479