Vulnerable conditions syndemic, depression, and suicidal ideation among school children in China: cross-sectional census findings

Mental health issues (depression and suicidal ideation) are increasingly common in children and emerge as escalating public health concerns. The syndemics that underline the importance of risk factor clustering provides a framework for intervention, but there is a lack of research on syndemics involving the adverse interactions of children's mental health problems. This study therefore examined the cumulative and synergistic effects of vulnerable conditions on depression and suicidal ideation among children in China. A mental health screening census of students in grades 5-12 was conducted from November 2022 to January 2023 in Nanling County, Anhui Province, China. The prevalence and co-occurrence of vulnerable conditions (unfavorable parental marital status, left-behind experience, bullying victimization, and self-harm behavior), depression, and suicidal ideation and the cumulative and synergistic effects of vulnerable conditions on depression and suicidal ideation were explored. Nearly a quarter of students (24.8%) reported at least two syndemic conditions. Overall, the prevalence of depression and suicidal ideation were 20.2% and 24.2% respectively. The odds of depression and suicidal ideation were higher for children with one or more vulnerable conditions and were ten times higher for children with three or more vulnerable conditions compared with those without any vulnerable condition. These four vulnerable conditions can increase the odds of depression and suicidal ideation by interacting synergistically with each other. Our findings signal the importance of addressing mental health syndemics among children in China by simultaneously considering concurrent vulnerable conditions.