From work-related trauma to suicidal ideation: a serial mediation model of posttraumatic stress and depression in rescue workers

Objectives: Rescue workers face frequent occupational trauma, increasing their risk for posttraumatic stress symptoms (PTSS), depression, and suicidal ideation. However, pathways linking trauma to suicidality remain poorly understood. This study investigated these mechanisms by testing a serial mediation model. Methods: From a larger survey of Swiss rescue workers, participants reporting suicidal ideation (n = 44) were matched by age, sex, and profession with a control group without suicidal ideation (n = 44). Symptomatology was assessed using validated questionnaires such as the Posttraumatic Stress Scale-10 (PTSS-10) for posttraumatic stress and the Brief Symptom Inventory (BSI) for depressive symptoms. Structural Equation Modeling (SEM) was employed to test a serial two-mediator model: Trauma Exposure - PTSS - Depressive Symptoms - Suicidal Ideation. Results: Participants with suicidal ideation had significantly higher levels of trauma, PTSS, and depressive symptoms. SEM confirmed an excellent model fit (χ² = 1.925, CFI = 1.000, RMSEA <.001) and a full mediation effect: trauma exposure was associated with PTSS, which in turn related to depressive symptoms, which were subsequently linked to suicidal ideation. The specific serial indirect pathway was significant (B = 0.143, p = .011), while the direct path from trauma to suicidal ideation was non-significant. The model explained 69.4% of the variance in suicidal ideation. Conclusion: The findings suggest a developmental pathway in which trauma exposure is associated with suicidal ideation through the sequential roles of PTSS and depressive symptoms. Consequently, suicide prevention for rescue workers should prioritize the management of post-traumatic and depressive symptoms to potentially disrupt this symptomatic progression.