RESUMEN
OBJECTIVES@#To investigate the differences in non-suicidal self-injury (NSSI) behaviors between only-child and non-only-child adolescents with mood disorders.@*METHODS@#A three-stage sampling method was used to perform a cross-sectional survey of 529 adolescents, aged 12-18 years, who had mood disorders and NSSI behaviors. These adolescents were sampled from the outpatient service of 20 mental hospitals in 9 provinces of China from August to November 2020. A self-made questionnaire was used to collect general demographic data. The Functional Assessment of Self-Mutilation, Beck Scale for Suicide Ideation, Kessler Psychological Distress Scale, Stress Mindset Measure-General, Multidimensional Scale of Perceived Social Support, Multidimensional Students' Life Satisfaction Scales, and Rosenberg Self-Esteem Scale were used to collect the information on self-injury behaviors and psychological factors in these adolescents.@*RESULTS@#A total of 529 adolescents with mood disorders and NSSI behaviors were surveyed, among whom 375 were only-child adolescents and 154 were non-only-child adolescents. Compared with the non-only-child group, the only-child group had a significantly higher total score of Functional Assessment of Self-Mutilation (P<0.05) .The type and frequency of self-injury in the only-child group were significantly higher than those in the non-only-child group (P<0.05). Psychological analysis showed that compared with the non-only-child group, the only-child group had a significantly lower score of self-esteem (P<0.05) and significantly higher scores of psychological distress and depressive symptoms (P<0.05). The multiple linear regression analysis showed that the score of suicidal ideation was positively correlated with the frequency of NSSI behaviors in both only-child and non-only-child adolescents with mood disorders (P<0.05); in the only-child adolescents, the level of self-esteem was negatively correlated with the frequency of NSSI behaviors (P<0.05), and the score of stress perception was positively correlated with the frequency of NSSI behaviors (P<0.05); in the non-only-child adolescents, the score of anxious emotion was positively correlated with the frequency of NSSI behaviors (P<0.05).@*CONCLUSIONS@#Among the adolescents with mood disorders and NSSI behaviors, the only-child adolescents tend to have a higher frequency of self-injury and poorer mental health, and therefore, the only-child adolescents with mood disorders and NSSI behaviors need more attention.