A. Adjusted LSM for Cortisol. In this linear mixed model, LSMs were adjusted for age, sex, pre-exposure social media addiction score, and pre-exposure cyberbullying score. Error bars indicate standard error. No significant group differences were observed at pre-exposure (adjusted P=.5739) or post-exposure (adjusted P=.1791). A significant increase in cortisol levels occurred from pre-exposure to post-exposure for the MDD group (LSM increase, 0.06 [SE, 0.02]; adjusted P=.0216) but not for the healthy control group (LSM decrease, −0.01 [SE, 0.01]; adjusted P=.5729). Greater cortisol levels represent a greater stress response. LSM indicates least squares mean; MDD, major depressive disorder. Figure 1B. Adjusted LSM for Amylase. In this linear mixed model, LSMs were adjusted for age, sex, pre-exposure social media addiction score, and pre-exposure cyberbullying score. Error bars indicate standard error. No significant group differences were observed at pre-exposure (adjusted P=.2292) or post-exposure (adjusted P=.5756). A significant increase in amylase levels occurred from pre-exposure to post-exposure for the MDD group (LSM increase, 38.58 [SE, 13.92]; adjusted P=.0216) but not for the healthy control group (LSM increase, 7.83 [SE, 8.85]; adjusted P=.5064). Greater amylase levels (U/mL) represent greater stress response. LSM indicates least squares mean; MDD, major depressive disorder.