Factors influencing non-suicidal self-injury in adolescents with mood disorders: Focusing on gender differences and only-child vs non-only-child disparities

Table 1 Univariate analysis of non-suicidal self-injury behavior in adolescents with mood disorders, n (%)/mean ± SD

Variables	NSSI group (n = 448)	Non-NSSI group (n = 172)	t/χ2	P value
Sociodemographic characteristics
Age (years)	15.36 ± 1.82	16.12 ± 1.75	-4.58	< 0.001
Gender			12.63	< 0.001
Male	126 (28.13)	68 (39.53)
Female	322 (71.82)	104 (60.47)
Sibling status			8.95	0.003
Only-child	296 (66.07)	92 (53.49)
Non-only-child	152 (33.93)	80 (46.52)
Family monthly income			15.72	0.001
< 5000	108 (24.11)	22 (12.79)
5000-10000	212 (47.32)	86 (50.00)
> 10000	128 (28.57)	64 (37.21)
Parental marital status			10.37	0.001
Married	364 (81.2500)	150 (87.2093)
Divorced/remarried	84 (18.7500)	22 (12.7907)
Parental education level			14.89	< 0.001
≤ High school	204 (45.5357)	58 (33.7209)
> High school	244 (54.4643)	114 (66.2791)
Residential area			1.70	0.184
Urban	312 (69.6429)	126 (73.2558)
Rural	136 (30.3571)	46 (26.7442)
Clinical factors
Duration of mood disorder (months)	14.82 ± 6.35	11.26 ± 5.87	6.73	< 0.001
Comorbid obsessive-compulsive symptoms	186 (41.5179)	42 (24.4186)	15.28	< 0.001
Psychological assessments
SCS self-warmth	31.85 ± 7.62	37.42 ± 8.15	-7.84	< 0.001
SCS self-coldness	51.63 ± 8.24	45.38 ± 7.96	8.36	< 0.001
ERQ cognitive reappraisal	20.76 ± 6.43	25.89 ± 6.71	-9.21	< 0.001
ERQ expressive suppression	17.58 ± 5.12	16.24 ± 4.87	3.02	0.002
K-10 score	36.82 ± 7.45	29.35 ± 6.98	11.54	< 0.001
CTQ total score	53.76 ± 10.82	45.21 ± 9.76	8.97	< 0.001
Family functioning
FACES III cohesion	42.38 ± 8.56	48.65 ± 9.12	-7.53	< 0.001
FACES III adaptability	38.74 ± 7.93	44.21 ± 8.45	-7.01	< 0.001

NSSI: Non-suicidal self-injury; SCS: Self-Compassion Scale; ERQ: Emotion Regulation Questionnaire; K-10: Kessler Psychological Distress Scale; CTQ: Childhood Trauma Questionnaire; FACES: Family Adaptation and Cohesion Evaluation Scales.

Table 2 Multivariate logistic regression analysis of non-suicidal self-injury behavior in adolescents with mood disorders

Variables	B	SE	Wald χ2	df	P value	OR (95%CI)
Gender (female = 1, male = 0)	0.629	0.214	8.643	1	0.003	1.876 (1.245-2.823)
Sibling status (only-child = 1, non-only-child = 0)	0.433	0.208	4.267	1	0.039	1.542 (1.036-2.298)
Duration of mood disorder (months)	0.081	0.020	15.32	1	< 0.001	1.084 (1.041-1.128)
Comorbid obsessive-compulsive symptoms (yes = 1, no = 0)	0.757	0.231	10.89	1	0.001	2.135 (1.384-3.298)
SCS self-warmth	-0.081	0.014	33.06	1	< 0.001	0.921 (0.894-0.949)
SCS self-coldness	0.055	0.013	17.18	1	< 0.001	1.056 (1.029-1.085)
ERQ cognitive reappraisal	-0.101	0.017	34.57	1	< 0.001	0.903 (0.872-0.935)
ERQ expressive suppression	0.021	0.018	1.334	1	0.248	1.021 (0.985-1.059)
K-10 score	0.097	0.015	41.89	1	< 0.001	1.102 (1.071-1.134)
CTQ total score	0.037	0.009	14.98	1	< 0.001	1.038 (1.019-1.058)
FACES III cohesion	-0.058	0.013	21.14	1	< 0.001	0.942 (0.918-0.967)
Parental marital status (divorced/remarried = 1, married = 0)	0.321	0.246	1.70	1	0.192	1.379 (0.854-2.223)
Parental education level (> high school = 1, ≤ high school = 0)	-0.284	0.201	2.002	1	0.157	0.752 (0.513-1.098)
Family monthly income (ref: < 5000 RMB)
5000-10000 RMB	-0.142	0.2387	0.3645	1	0.546	0.866 (0.538-1.394)
> 10000 RMB	-0.312	0.2543	1.4987	1	0.221	0.731 (0.449-1.192)
Constant	-12.84	1.876	46.53	1	< 0.001	2.6741 × 10-6

OR: Odds ratio; CI: Confidence interval; SCS: Self-Compassion Scale; ERQ: Emotion Regulation Questionnaire; K-10: Kessler Psychological Distress Scale; CTQ: Childhood Trauma Questionnaire; FACES: Family Adaptation and Cohesion Evaluation Scales.

Table 3 Univariate analysis of non-suicidal self-injury characteristics between male and female adolescents with mood disorders, n (%)/mean ± SD

Variables	Male (n = 126)	Female (n = 322)	t/χ2	P value
Sociodemographic characteristics
Age (years)	15.48 ± 1.76	15.31 ± 1.84	0.89	0.371
Sibling status			2.13	0.143
Only-child	82 (65.08)	214 (66.46)
Non-only-child	44 (34.92)	108 (33.54)
Family monthly income			10.24	0.006
< 5000	22 (17.46)	86 (26.71)
5000-10000	64 (50.79)	148 (45.96)
> 10000	40 (31.75)	88 (27.33)
Parental marital status			1.56	0.210
Married	104 (82.54)	260 (80.75)
Divorced/remarried	22 (17.46)	62 (19.25)
Parental education level			8.97	0.002
≤ High school	48 (38.10)	156 (48.76)
> High school	78 (61.90)	166 (51.24)
Residential area			0.98	0.321
Urban	88 (69.84)	224 (69.57)
Rural	38 (30.16)	98 (30.43)
Clinical factors
Duration of mood disorder (months)	14.62 ± 6.51	14.91 ± 6.28	-0.45	0.646
Comorbid obsessive-compulsive symptoms	52 (41.27)	134 (41.61)	0.006	0.933
Psychological assessments
SCS self-warmth	33.96 ± 7.28	30.82 ± 7.65	4.12	< 0.001
SCS self-coldness	49.25 ± 8.03	52.58 ± 8.21	-4.01	< 0.001
ERQ cognitive reappraisal	22.58 ± 6.17	20.03 ± 6.45	4.23	< 0.001
ERQ expressive suppression	17.24 ± 5.03	17.72 ± 5.15	-0.98	0.3245
K-10 score	34.52 ± 7.18	37.68 ± 7.41	-4.35	< 0.001
CTQ total score	50.83 ± 10.26	54.87 ± 10.89	-3.84	< 0.001
Family functioning
FACES III cohesion	44.62 ± 8.31	41.45 ± 8.59	3.67	< 0.001
FACES III adaptability	39.21 ± 7.86	38.52 ± 7.95	0.89	0.372

SCS: Self-Compassion Scale; ERQ: Emotion Regulation Questionnaire; K-10: Kessler Psychological Distress Scale; CTQ: Childhood Trauma Questionnaire; FACES: Family Adaptation and Cohesion Evaluation Scales.

Table 4 Comparison of non-suicidal self-injury frequency and methods between male and female adolescents, n (%)

Variables	Male (n = 126)	Female (n = 322)	χ2	P value
NSSI frequency (past year)			9.874	0.007
1-4 times	58 (46.03)	102 (31.68)
≥ 5 times	68 (53.97)	220 (68.32)
NSSI methods
Cutting	64 (50.79)	202 (62.73)	6.784	0.009
Scratching	56 (44.44)	189 (58.70)	9.215	0.002
Hitting	65 (51.58)	148 (45.96)	1.568	0.210
Burning	22 (17.46)	58 (18.01)	0.042	0.835
Head-banging	49 (38.89)	102 (31.68)	2.894	0.089
Hair-pulling	32 (25.40)	82 (25.47)	0.001	0.982
Interfering with wound healing	38 (30.16)	138 (42.86)	8.124	0.004

NSSI: Non-suicidal self-injury.

Table 5 Gender-specific multivariate logistic regression analysis of non-suicidal self-injury frequency

Variables	Male (n = 126)				Female (n = 322)
	B	SE	OR (95%CI)	P value	B	SE	OR (95%CI)	P value
K-10 score	0.116	0.032	1.123 (1.056-1.194)	< 0.001	0.021	0.0207	1.021 (0.981-1.063)	0.298
CTQ total score	0.020	0.018	1.021 (0.984-1.058)	0.256	0.044	0.013	1.045 (1.018-1.073)	< 0.001
SCS self-warmth	-0.031	0.024	0.969 (0.922-1.017)	0.205	-0.101	0.018	0.903 (0.867-0.941)	< 0.001
SCS self-coldness	0.032	0.025	1.0333 (0.983-1.085)	0.192	0.028	0.019	1.029 (0.991-1.068)	0.136
ERQ cognitive reappraisal	-0.041	0.028	0.959 (0.906-1.016)	0.152	-0.119	0.023	0.887 (0.846-0.931)	< 0.001
FACES III cohesion	-0.081	0.031	0.921 (0.876-0.969)	0.001	-0.024	0.017	0.975 (0.942-1.010)	0.166
Family monthly income (> 10000 vs < 5000 RMB)	-0.214	0.321	0.807 (0.446-1.461)	0.498	-0.187	0.205	0.822 (0.556-1.215)	0.328
Parental education level (> high school vs ≤ high school)	-0.321	0.287	0.725 (0.428-1.223)	0.235	-0.215	0.189	0.807 (0.556-1.172)	0.258
Constant	-5.874	1.896	0.002 (0.000-0.038)	< 0.001	-2.145	1.023	0.116 (0.013-1.032)	0.035

OR: Odds ratio; CI: Confidence interval; K-10: Kessler Psychological Distress Scale; CTQ: Childhood Trauma Questionnaire; SCS: Self-Compassion Scale; ERQ: Emotion Regulation Questionnaire; FACES: Family Adaptation and Cohesion Evaluation Scales.

Table 6 Univariate analysis of non-suicidal self-injury characteristics between only-child and non-only-child adolescents, n (%)/mean ± SD

Variables	Only-child (n = 296)	Non-only-child (n = 152)	t/χ2	P value
Sociodemographic characteristics
Age (years)	15.32 ± 1.85	15.43 ± 1.78	-0.625	0.533
Gender			1.037	0.309
Male	82 (27.70)	44 (28.95)
Female	214 (72.30)	108 (71.05)
Family monthly income			4.216	0.122
< 5000	72 (24.32)	36 (23.68)
5000-10000	144 (48.65)	68 (44.74)
> 10000	80 (27.03)	48 (31.58)
Parental marital status			6.895	0.009
Married	229 (77.36)	135 (88.81)
Divorced/remarried	67 (22.64)	17 (11.18)
Parental education level			3.126	0.077
≤ High school	136 (45.95)	68 (44.74)
> High school	160 (54.05)	84 (55.26)
Residential area			0.587	0.444
Urban	206 (69.59)	106 (69.74)
Rural	90 (30.41)	46 (30.26)
Clinical factors
Duration of mood disorder (months)	14.91 ± 6.42	14.65 ± 6.21	0.439	0.661
Comorbid obsessive-compulsive symptoms	124 (41.89)	62 (40.79)	0.068	0.795
Psychological assessments
SCS self-warmth	30.75 ± 7.58	33.92 ± 7.26	-4.587	< 0.001
SCS self-coldness	52.86 ± 8.15	49.21 ± 8.03	4.321	< 0.001
ERQ cognitive reappraisal	19.85 ± 6.37	22.46 ± 6.12	-4.218	< 0.001
ERQ expressive suppression	17.62 ± 5.08	17.51 ± 5.17	0.214	0.830
K-10 score	37.95 ± 7.38	34.62 ± 7.15	4.785	< 0.001
CTQ total score	54.12 ± 10.76	53.15 ± 10.89	0.824	0.410
Family functioning
FACES III cohesion	40.85 ± 8.47	44.92 ± 8.23	-5.214	< 0.001
FACES III adaptability	38.42 ± 7.89	39.25 ± 7.96	-1.021	0.307

SCS: Self-Compassion Scale; ERQ: Emotion Regulation Questionnaire; K-10: Kessler Psychological Distress Scale; CTQ: Childhood Trauma Questionnaire; FACES: Family Adaptation and Cohesion Evaluation Scales.

Table 7 Comparison of non-suicidal self-injury frequency and methods between only-child and non-only-child adolescents, n (%)

Variables	Only-child (n = 296)	Non-only-child (n = 152)	χ2	P value
NSSI frequency (past year)			11.24	< 0.001
1-4 times	82 (27.70)	63 (41.45)
≥ 5 times	214 (72.30)	89 (58.55)
NSSI methods
Cutting	191 (64.53)	75 (49.34)	10.87	0.001
Scratching	176 (59.46)	69 (45.39)	8.652	0.003
Hitting	148 (49.93)	83 (54.61)	0.897	0.343
Burning	52 (17.57)	28 (18.42)	0.058	0.809
Head-banging	98 (33.11)	53 (34.87)	0.128	0.720
Hair-pulling	78 (26.35)	36 (23.68)	0.428	0.512
Interfering with wound healing	134 (45.27)	42 (27.63)	12.58	< 0.001

NSSI: Non-suicidal self-injury.

Table 8 Sibling status-specific multivariate logistic regression analysis of non-suicidal self-injury frequency

Variables	Only-child (n = 296)				Non-only-child (n = 152)
	B	SE	OR (95%CI)	P value	B	SE	OR (95%CI)	P value
K-10 score	0.111	0.028	1.118 (1.057-1.183)	< 0.001	0.093	0.032	1.097 (1.028-1.170)	0.004
SCS self-warmth	-0.108	0.021	0.897 (0.856-0.941)	0.0000	-0.042	0.029	0.958 (0.903-1.017)	0.152
SCS self-coldness	0.031	0.020	1.032 (0.991-1.074)	0.132	0.028	0.026	1.029 (0.977-1.083)	0.276
ERQ cognitive reappraisal	-0.038	0.022	0.962 (0.920-1.006)	0.084	-0.021	0.028	0.978 (0.925-1.035)	0.456
FACES III cohesion	-0.091	0.025	0.912 (0.874-0.952)	< 0.001	-0.032	0.031	0.967 (0.910-1.028)	0.298
Parental marital status (divorced/remarried vs married)	0.287	0.214	1.332 (0.894-1.987)	0.1658	0.312	0.328	1.367 (0.735-2.541)	0.318
Constant	-4.215	1.287	0.015 (0.002-0.121)	< 0.001	-2.874	1.568	0.055 (0.004-0.721)	0.028

OR: Odds ratio; CI: Confidence interval; K-10: Kessler Psychological Distress Scale; SCS: Self-Compassion Scale; ERQ: Emotion Regulation Questionnaire; FACES: Family Adaptation and Cohesion Evaluation Scales.