Adolescent non-suicidal self-injury: The moderating influence of social support utilization on depression

Table 1 Comparison of characteristics between the non-non-suicidal self-injury and non-suicidal self-injury groups, n (%)

Variables	Non-NSSI (n = 56)	NSSI (n = 258)	t/χ²	P value
Age, mean (SD)	14.5 (1.8)	14.1 (1.5)	2.8	0.216
Gender			12.1	0.011a
Male	20 (35.7)	38 (14.7)
Female	36 (64.3)	220 (85.3)
Only child			4.6	0.114
No	24 (42.9)	154 (59.7)
Yes	32 (57.1)	104 (40.3)
Grade			4.2	0.216
Primary	4 (7.1)	31 (12.0)
Junior	36 (64.3)	182 (70.5)
Senior	16 (28.6)	45 (17.4)
Study status			9.2	0.157
In school	17 (30.4)	42 (16.3)
Suspension	10 (17.9)	74 (28.7)
Leave	26 (46.4)	136 (52.7)
Return	2 (3.6)	5 (1.9)
Dropout	1 (1.8)	1 (0.4)
Academic performance			2.0	0.458
Top third	12 (21.4)	63 (24.4)
Middle third	35 (62.5)	136 (52.7)
Bottom third	9 (16.1)	59 (22.9)
Interpersonal relationships			7.3	0.114
Good	17 (30.4)	57 (22.1)
Average	32 (57.1)	124 (48.1)
Poor	7 (12.5)	77 (29.8)
Economic status			4.4	0.458
Much better	2 (3.6)	9 (3.5)
Better	20 (35.7)	75 (29.1)
Average	31 (55.4)	143 (55.4)
Worse	1 (1.8)	25 (9.7)
Much worse	2 (3.6)	6 (2.3)
Father's education			2.7	0.601
≤ Junior high	22 (39.3)	85 (32.9)
Senior high	11 (19.6)	75 (29.1)
College	10 (17.9)	43 (16.7)
Bachelor	10 (17.9)	47 (18.2)
≥ Master	3 (5.4)	8 (3.1)
Mother's education			4.5	0.458
≤ Junior high	22 (39.3)	98 (38.0)
Senior high	12 (21.4)	76 (29.5)
College	10 (17.9)	42 (16.3)
Bachelor	8 (14.3)	36 (14.0)
≥ Master	4 (7.1)	6 (2.3)
Childhood adversity			0.8	0.458
No	17 (30.4)	98 (38.0)
Yes	39 (69.6)	160 (62.0)

^aP < 0.05.

NSSI: Adolescents with major depressive disorder and non-suicidal self-injury group; non-NSSI: Adolescents with major depressive disorder without non-suicidal self-injury group; P values were adjusted using the FDR method. t-tests were used for continuous variables (age) and χ² tests for categorical variables. NSSI: Non-suicidal self-injury.