Adolescents’ Experiences of Close Relatives Having Physical Illness, Mental Illness, Addiction/Gambling Disorders, or Death Are Associated with Poor Mental Health and Non-Suicidal Self-Injury

Adolescents’ lives are negatively influenced by experiences of close relatives having severe health conditions. This study aimed to investigate the associations between adolescents’ experiences of close relatives with severe health conditions (RSHCs) and poor mental health and non-suicidal self-injury (NSSI). Cross-sectional population-based data on 15–18-year-olds (n = 3483) in Sörmland, Sweden, were used to analyse the associations between RSHC experiences, such as physical illness, mental illness, addiction/gambling disorders, or death, and poor mental health and NSSI. Logistic regression models (odds ratios) were generated for having one or multiple types of RSHC experiences in different combinations, adjusting for background factors and protective factors for mental health, and stratifying by gender. Adolescents reporting multiple types of RSHC experiences had significantly increased odds ratios for poor mental health (1.74–3.07) or NSSI (1.83–3.02) compared with peers without such experiences. Adjustments for mental health protective factors attenuated the associations with poor mental health or NSSI. These associations remained significant among girls with multiple types of RSHC experiences, while boys’ vulnerabilities included having a relative who had died or had an addiction/gambling disorder. In conclusion, adolescents with RSHC experiences are at increased risk of poor mental health and NSSI. This vulnerability is most pronounced among girls with multiple RSHC experiences and especially for NSSI.