Songsin N.Kingkaew W.M.Siladlao S.Somporn K.Pianjing P.Inthiraj A.Chusuton S.Wannapaschaiyong P.Mahidol University2026-05-232026-05-232026-02-04Science Engineering and Health Studies Vol.20 (2026)https://repository.li.mahidol.ac.th/handle/123456789/116819Depression represents a prominent public health concern present within diverse populations worldwide, and it is known to manifest across all genders as well as age groups. The current investigation constitutes a cross-sectional study aimed at exploring negative automatic thinking, social support, and depression among senior high school students in Samut Songkhram province, Thailand. The study sample consists of 373 senior high school students who were selected using a stratified random sampling method. Data were collected using online questionnaires. Data analysis was conducted using inferential statistics and the Pearson correlation coefficient. The study found that overall automatic negative thoughts were at a low level, while overall social support was at a moderate level (M = 3.07, SD = 0.80), and depression was at a moderate level. The analysis revealed a statistically significant positive correlation between negative thoughts and depression among high school students. Additionally, there was a statistically significant negative correlation between social support and depression. The results of this study will be valuable in guiding the development of teaching and learning strategies as well as mental health services that support student learning. They will also aid in planning for the care and prevention of depression in the future.MultidisciplinaryArticleSCOPUS10.69598/sehs.20.260500032-s2.0-10503855421326300087