A daily-life study of interpersonal stressors and alcohol use in individuals with borderline personality disorder and community controls.

BACKGROUND: Interpersonal stressors (ISs) are major factors in relapse in alcohol use disorder (AUD) and are theorized to play a role in drinking behaviors. Past work has examined this association using ecological momentary assessment (EMA), but the unique effects of rejections and disagreements on alcohol use are unknown. Research suggests the two ISs functionally differ and may display distinct associations with drinking. Further, these associations may differ in people with borderline personality disorder (BPD), a population reporting frequent IS and co-occurring AUD. METHODS: 113 drinkers (community: n = 59; BPD: n = 54) reported alcohol use and ISs using EMA for 21 days. Using generalized estimating equations, we expected that rejection and disagreement would predict increased likelihood of drinking each day. We examined both cumulative (throughout each day) and immediate momentary effects of ISs predicting subsequent drinking on that same day. Further, we predicted that these associations would be stronger in individuals with BPD. RESULTS: Greater rejections throughout the day were associated with a reduced likelihood of drinking that day (OR = 0.56, 95 % CI:[0.32, 0.97], p < .040). In contrast, disagreements immediately prior to drinking were associated with an increased likelihood of drinking that day (OR = 0.60, 95 % CI:[1.02, 2.50], p = .039). However, the effect of disagreement on drinking was moderated by BPD diagnosis (OR = 2.56, 95 % CI:[1.13, 5.80], p = .025), such that the effect was only present for individuals with BPD. CONCLUSIONS: Assessing ISs as an aggregate predictor may mask potentially opposite effects on alcohol use. Additionally, disagreements may be a risk factor for subsequent alcohol use in BPD.