The differential roles of trauma, posttraumatic stress disorder, and comorbid depressive disorders on suicidal ideation in the elderly population

Abstract

Objective: Although depression is the strongest predictor for the full spectrum of suicidal ideation, several other mental disorders, eg, posttraumatic stress disorder (PTSD), are associated with suicidal ideation too. This study investigates whether suicidal ideation is specifically associated with PTSD or if this association is fully or partially mediated by comorbid depressive disorders.

Method: A representative sample of 1,659 people aged 60-85 years from the German general population was examined by using self-rating instruments for PTSD, depression, and suicidal ideation in May and June 2008 in a cross-sectional study. Participants were diagnosed with PTSD when they met criteria A, B, C, and D for PTSD according to DSM-IV-TR. Suicidal ideation was used as the primary outcome measure.

Results: In our sample, 7.3% of subjects reported suicidal ideation within the last 2 weeks. Suicidal ideation was associated with a higher number of traumatic experiences (mean = 1.13 vs 0.78; t = -3.20; P ≤ .001) and prevalence of PTSD (12.4% vs 3.4%, χ2 = 23.39, P < .001) than in subjects without suicidal ideation. In logistic regression analyses including age and sex, traumatic experiences were associated with suicidal ideation (OR = 1.16, P = .011). After including PTSD in the model, this association was fully explained by PTSD. Moreover, PTSD was associated with suicidal ideation (OR = 3.33, P < .001), but after including depression in the model, the association of PTSD and suicidal ideation was fully mediated by depression (OR = 1.61, P < .001).

Conclusions: The results of our study indicate that PTSD is associated with suicidal ideation, but this association was fully explained by comorbid depressive symptoms in the elderly general population. Thus, screening for depressive symptoms as well as administering an appropriate therapy seems the best way to prevent suicide attempts in the elderly, even in those patients with traumatic experiences and/or PTSD.