Facing Emotions: Between- and Within-Sessions Changes in Facial Expression During Psychological Treatment for Depression

The main diagnostic criteria for major depressive disorder (MDD) are consistent experiences of high levels of negative emotions and low levels of positive emotions. Therefore, modification of these emotions is essential in the treatment of MDD. In the current study, we harnessed a computational approach to explore whether experiencing negative emotions during psychological treatment is related to subsequent changes in these emotions. Facial expressions were automatically extracted from 175 sessions of 58 patients with MDD. Within sessions, a U-shaped trajectory of change in valence was observed in which patients expressed an increase in negative emotions in the middle of the session. Between sessions, a consistent increase in valence was observed. A trajectory of within-sessions decrease followed by an increase in valence was positively associated with greater perceived positive emotions and subsequent decreases in depressive symptoms. These findings highlight the importance of targeting negative emotions during treatment to achieve more favorable outcomes.