Recent exposure to others' confided suicidal thoughts and risk of self-harm and suicidality among adolescents

Few studies have investigated the contagion effects of exposure to others' confided suicidal thoughts among adolescents. The aim of this study was to investigate whether recent real-world exposure to confided suicidal thoughts was associated with adolescent self-harm and suicidality within one month, and if so, to determine the related risk and protective factors. A total of 5,879 Taiwanese first-year senior high school students participated in this study and completed on-line questionnaires regarding their experience of exposure to confided suicidal thoughts, self-harm and suicidality, socio-demographic information, Patient Health Questionnaire 9-item, Multi-Dimensional Support Scale, Rosenberg Self-Esteem Scale, and alcohol and cigarette use. Of the enrolled adolescents, 3.4% had been exposed to confided suicidal thoughts (N = 200) within one month. The most common source of exposure was friends (N = 186). After controlling for a large variety of confounders, the adolescents with recent exposure to others' suicidal thoughts were four times more likely to harm themselves within one month (OR = 3.77; 95% CI: 2.26 - 6.30). The risks of suicidal ideation and suicide plans were also markedly increased (both OR = 5.15; 95% CI: 3.48 - 7.64 and 2.78 - 9.52, respectively). The risk ratios were highest if the source of exposure was from parents, and the contagion effects were dose-dependent. Support from parents and teachers could protect the adolescents from the impact of contagion. Our results suggest a contagion effect of exposure to confided suicidal thoughts among adolescents. Parents and school personnel should be aware of this and provide assistance for those in need.