Who's in charge? Linguistic exploration of social media posts reveals reduced sense of agency in dissociation.

Sense of Agency (SoA), the subjective experience of initiating and controlling one's actions, is a critical component of self-perception and consciousness, and is often degraded in different psychopathologies. Individuals with dissociation seem to have diminished SoA, but it is yet unknown whether this affects communication with their surroundings. This study employs Natural Language Processing (NLP) to examine linguistic markers of SoA in dissociation, focusing on passive voice usage as an indicator of diminished agency. A dataset of 26 017 posts was extracted from 'Reddit' forums concerning dissociation and maladaptive daydreaming (a suggested dissociative disorder), and for comparison, depression, anxiety, and social anxiety. Passive voice usage was measured using spaCy's NLP framework, and verb tense distributions were analysed to explore additional potential linguistic markers of agency. Negative binomial regression models were used to compare passive voice usage across groups, controlling for word count. The dissociation group, but not the maladaptive daydreaming group, exhibited significantly greater use of passive voice compared to the general psychopathology control group (IRR = 1.10, P < .001). Additionally, when examining the three psychopathology control subgroups separately (depression, anxiety, and social anxiety), no significant difference was found between the depression and dissociation groups in passive voice usage. These findings suggest that diminished SoA is a core feature of dissociation, reflected in linguistic patterns. The results highlight the usefulness of language-based big data investigations in understanding the self-experience in psychopathology research.