Behavioral Rigidity in Residential Treatment for Substance Use Disorder (RIG-TD)

Behavioral rigidity, the tendency to maintain inflexible patterns of thinking and acting despite changing circumstances, is a common feature in substance use disorders, depression, and anxiety. This observational study aims to measure behavioral rigidity as a dynamic, transdiagnostic process in patients undergoing residential treatment for substance use. Using a longitudinal intensive repeated-measures design, participants complete weekly assessments of cognitive reactivity (Automatic Thoughts Questionnaire-8 item version, ATQ-8), behavioral activation (Behavioral Activation for Depression Scale, BADS), and experiential avoidance. A Behavioral Rigidity Index (BRI) is derived from these measures. Additionally, natural language processing (NLP) is applied to therapy session transcripts to quantify linguistic absolutism (e.g., use of words like "always," "never") and affective polarity. Bayesian multilevel models examine whether rigidity predicts current and next-week clinical status. The study also explores whether linguistic markers add unique predictive value beyond self-reports. Results may inform personalized monitoring and interventions targeting psychological inflexibility in addiction treatment.