Automatic quantification of hand gestures in current and remitted Major Depressive Disorder during oral expression

Nonverbal behavior plays a crucial role in social interactions and may provide insights into Major Depressive Disorder (MDD). While previous research suggests that hand gesture deficits are linked to depression, it remains unclear whether these deficits are state-dependent or persist beyond active illness. This study utilized an automated, video-based tool to quantify spontaneous hand gestures in individuals with current (cMDD) and remitted (rMDD) MDD during oral expression. A total of 145 participants (97 rMDD and 49 cMDD) completed a recorded gesture-elicitation task, and hand movement trajectories were extracted using video-based body tracking. Results revealed that individuals with current MDD exhibited significantly fewer gestures per minute compared to remitted individuals (p = .016, d = 0.38). Furthermore, gesture frequency negatively correlated with depressive symptom severity (r = -0.17, p = .046) and observational measures of psychomotor retardation (r = -0.23, p = .012). These findings suggest that gesture deficits are more strongly tied to the active state of depression rather than serving as a marker of vulnerability or a scar from previous depressive episodes. Automated gesture analysis provides an objective and scalable method for assessing nonverbal behavior in MDD. Future research should explore its clinical utility as a biomarker for symptom severity and treatment response.