This study explores the relative contributions and psychological mechanisms of the effects of family (father–child and mother–child) and school (teacher–student and student–student) interpersonal relationships on depression in elementary school children. The participants (n = 20,629) were elementary school children (48.19% male) aged nine to 13 years from Southwest China during the COVID-19 pandemic. They voluntarily completed questionnaires regarding parent–child, teacher–student, and student–student relationships, as well as academic stress and self-esteem. The results indicate that the effect of family interpersonal relationships on children’s depression was stronger than that of school interpersonal relationships. The predictive effects of father–child and mother–child relationships on children’s depression did not significantly differ; however, the effect of student–student relationships was significantly stronger than that of teacher–student relationships. Academic stress partially mediated the effect of interpersonal relationships on depression in elementary school children. The effects of family interpersonal relationships and academic stress on depression were moderated by self-esteem. These findings underscore the disparities and mechanisms pertaining to the impacts of diverse interpersonal associations on children’s depression, thus signifying significant implications for the advancement of research and intervention strategies aimed at addressing this issue.

Suicidal ideation and behavior are critical psychological crises among children and adolescents, posing significant concerns for their mental health and safety. This cross-sectional study investigated the factors and underlying psychological mechanisms of suicidal ideation in adolescents. A total of 6474 middle school students from Sichuan and Hebei provinces, China, participated in the study. Data were collected using the Self-Assessment of Suicidal Ideation Scale, the Parental Psychological Control Scale, the Meaning in Life Scale, and the Basic Psychological Needs Scale. Statistical analyses, including mediation and chain mediation analyses, were conducted to examine the relationships between parental psychological control, basic psychological needs, meaning in life, and suicidal ideation. The results revealed the following: (1) Parental psychological control positively predicted suicidal ideation in middle school students; (2) basic psychological needs mediated the relationship between parental psychological control and suicidal ideation; (3) meaning in life mediated the relationship between parental psychological control and suicidal ideation; (4) basic psychological needs and meaning in life together played a chain-mediating role in this relationship. These findings highlight the importance of addressing parental psychological control and fostering a supportive family environment to meet adolescents’ psychological needs, enhance their sense of life meaning, and reduce suicidal ideation. Insights from this study provide valuable guidance for prevention and intervention strategies aimed at safeguarding adolescents’ mental health and well-being.