Prior 8-month substance use trajectories predict psychological functioning at start of residential treatment

This study explores trajectories of substance use days over the eight months prior to residential treatment among at-risk, diverse women with SUD and assess whether trajectories are linked to psychological functioning and drug/alcohol relapse. Data are from n=245 mostly Hispanic/Latina women undergoing residential SUD treatment. Group-Based Trajectory Modeling identified trajectories of substance use days, measured with the Timeline Followback (TLFB) over the eight months preceding treatment. We compared psychological functioning (measured with the Five Facet Mindfulness Questionnaire-Short Form, FFMQ-SF; Difficulties in Emotion Regulation Scale, DERS; and Depression, Anxiety, and Stress Scale, DASS) and relapse by trajectory. We identified five groups: Low Days, Start High/Early Decrease, Start High/Middle Decrease, High Days/Late Decrease, and Recent Increase/Late Decrease. The High Days/Late Decrease group had higher DERS scores compared with the Low Days and Start High/Middle Decrease groups (p<.001 for both comparisons), and higher DASS scores compared with the Low Days, Start High/Early Decrease, and Start High/Middle Decrease groups (p<.0125 for all comparisons). Substance use trajectories representing a high proportion of using days proximal to treatment predicted worse psychological functioning. It may be worthwhile to develop lower-burden measures that capture substance use trajectories.