Drinking motives moderate daily-life associations between affect and alcohol use in individuals with borderline personality disorder.

People often report drinking to cope with negative affect (NA) or to enhance positive affect (PA). However, findings from daily life studies examining the interaction of motives and affect to predict alcohol use are mixed. Individuals with borderline personality disorder (BPD) may be particularly susceptible to drinking for the purpose of changing affective states, representing a population in which these patterns may be more readily identifiable in daily life. We tested whether drinking motives moderate daily life associations between affect and drinking in individuals with BPD. Regular drinkers with BPD (N = 54; 81.5% female) completed ecological momentary assessments approximately 6-10 times daily for 21 days. We tested whether the interactions between (a) person-level coping motives and NA so far that day (i.e., cumulative-average NA), and (b) person-level enhancement and cumulative-average PA were associated with subsequent drinking. We also tested whether effects differed for the initiation versus continuation of a drinking episode. Using generalized estimating equations, the interaction between coping and cumulative-average NA was positively associated with momentary drinking, with some evidence for a stronger relation during the continuation of drinking. The interaction between enhancement motives and cumulative-average PA was positively associated with initiation but negatively associated with continuation of drinking. Our novel approach of using cumulative-average affect and distinguishing initiation and continuation of drinking allowed us to examine differential momentary patterns across the drinking episode, and results suggest that awareness of motives as well as affect leading up to and during drinking may be a useful intervention target. (PsycInfo Database Record (c) 2020 APA, all rights reserved).