Protective factors for suicidal ideation: a prospective study from adolescence to adulthood

Adolescent suicidality is associated with negative outcomes in adulthood. Suicide prevention has traditionally focused on identifying risk factors, yet suicide rates have remained stable. With suicidality often going undetected—especially suicidal ideation, further knowledge about protective factors is needed. The main objective of this study was to investigate potential protective factors for suicidal ideation from adolescence to adulthood. The study employed longitudinal population survey data, “Youth and Mental Health Study” consisting of self-reports at two-time points (mean age 14.9, SD = 0.6 and 27.2, SD = 0.6) ( n = 2423 and n = 1198). Protective factors (at individual, social and environmental level) were selected based on a priori knowledge. Internal consistency of scales was analyzed using McDonald’s omega. We used a linear mixed model with suicidal ideation as the dependent variable, time-points, a protective factor variable and their interaction as covariates, and individual participant as random effects. We adjusted for sex and also conducted separate analyses for males and females. The Benjamini–Hochberg procedure was used to adjust p -values for multiple hypotheses. Investigated protective factors were associated with temporal change in suicidal ideation (significant interactions). For both sexes, less emotion-orientated coping, higher self-perception scores, greater levels of physical activity and higher school wellbeing/connectedness were protective factors for suicidal ideations. Secure attachment and higher family function were protective factors for females only. The effects in adolescence were mostly maintained in adulthood. In this study, several protective factors for suicidal ideation persisted into adulthood, with distinct differences between males and females.