The Role of Interdisciplinary Convergence for Mental Health Among Korean Military Servicemen: Focusing on Depression and Salivary Dehydroepiandrosterone-Sulfate

(1) Background/Objectives: The purpose of this study was to examine the effectiveness of the "Thank You, Sorry, Love" (TSL) program for improving relationships on mental health and hormones of military soldiers in Korea. (2) Methods: We focused on soldiers' levels of depression and salivary DHEA-S. The effectiveness evaluation of the program used the pretest-posttest control group design, one of the Quasi-experimental design models. The program evaluation used a quasi-experimental design with a pre-test, post-test, and a follow-up for a treatment group and a control group. The sample comprised 40 military soldiers, who were divided into an experimental group (<i>n</i> = 20) receiving the TSL intervention and a control group (<i>n</i> = 20) without intervention. The study was conducted from June to September 2016, and the effectiveness of the intervention was evaluated through pre-test, post-test, and four-week follow-up tests. (3) Results: Our results revealed that soldiers' depression and DHEA-S levels significantly differed between the two groups. During the analysis of the program's effectiveness in which the pre-test was controlled, a statistically significant difference was found between the groups in the post-test (F = 12.666, <i>p</i> < 0.01, ES = 0.255) and the follow-up test (F (1, 39) = 13.319, <i>p</i> < 0.01, ES = 0.265) in DHEA-S. (4) Conclusions: These findings imply that the TSL program can be an effective intervention for soldiers suffering from depression while helping to produce clinical guidelines that could be made available in the field of military social work in Korea, which are still in their beginning stages.