Depression, posttraumatic stress, and suicidal ideation: A linkage study in Taiwanese army

Background: Symptoms of poststress traumatic stress disorder (PTSD) and depression are intertwined in suicide ideation (SI) in military personnel. The interpersonal psychological theory (IPT) of suicide is proposed that the presence of thwarted belongingness (TB) and perceived burdensomeness (PB) produces the desire for suicide. To clarify the putative moderating effect of IPT on the complex-mediated moderation relationship among symptoms of soldiers' PTSD, depression, and SI, we did a cross-section study through recruiting military personnel in three camps in northern Taiwan. Methods: We recruited 759 active-duty soldiers (male: female = 579: 180) from three troops in northern Taiwan. They were asked to fill out copies of questionnaire according to their current two-week situation for our analyzing the study data. Results: In this study, we found that the pathway from soldiers' PTSD symptom to SI was positively and significantly mediated through their depression (p < 0.001), and that the pathway from their PTSD to depression was positively and significantly moderated by both PB (p < 0.05) and thwarted belongingness (p < 0.05). Comparing with male counterparts, the female soldiers, although significantly and relatively younger in age (p < 0.001), suffered from significantly higher levels of depression (p < 0.05) without significant sex difference in the magnitudes of PTSD symptoms. Conclusion: This study revealed the moderating effects of IPT on the pathway from PTSD to depression and SI among soldiers. Sex difference, although is subtle, can be essential in military suicide prevention and treatments for cases with PTSD symptoms.