Within-person affect dynamics among individuals in residential treatment for opioid use disorder: An ecological momentary assessment study.

Ecological momentary assessment is increasingly leveraged to better understand affective processes underlying substance use disorder treatment and recovery. Research in this area has yielded novel insights into the roles of mean levels of positive affect (PA) and negative affect (NA) in precipitating drug craving and substance use in daily life. Little of the extant substance use disorder treatment research, however, considers dynamic patterns of PA and NA, separately or in relation to one another, or how such patterns may differ from those observed among nonclinical samples. The current ecological momentary assessment study examined between-person differences in within-person affect dynamics-including intensity, variability, instability, inertia, polarity, and spillover-among patients in residential treatment ( = 73) for opioid use disorder (OUD), both collectively and separately according to posttreatment relapse status, relative to a demographically similar nonclinical comparison group ( = 37). The results revealed no group differences in PA dynamics. The OUD group did, however, report higher average NA intensity and within-day variability relative to the comparison group. Furthermore, relative to the comparison group, OUD patients who relapsed within 120 days posttreatment exhibited greater linear declines in NA intensity across days, whereas OUD patients who did not relapse demonstrated weaker affect polarity (i.e., the within-person correlation between PA and NA). Although PA dynamics alone did not differ between groups, weaker affect polarity differentiated OUD patients who avoided relapse from the comparison group. The capacity to experience PA separately from fluctuations in NA may reflect an adaptive tendency that could reduce vulnerability to relapse among individuals in OUD treatment. (PsycInfo Database Record (c) 2025 APA, all rights reserved).