Integrating invalidation and minority stress theories to model daily change in personality pathology.

People with personality disorders (PDs) tend to experience invalidation in their daily life-others seem to disregard, reject, or punish their psychological experiences (e.g., emotions and self-concept). Our study aimed to (a) examine within-person covariation in day-to-day perceived invalidation and PD symptom severity and (b) explore minority stress as a form of invalidation-one that targets aspects of people's minoritized identities. We recruited 170 community adults and 339 undergraduate students, oversampling from sexual/gender and ethnic/racial minoritized groups, to complete daily surveys of invalidation, minority stress, and PD features over 2 weeks. We observed that daily invalidation (r = .35) and, to a smaller extent, minority stress (rs = .22-.23) had meaningful within-person correlations with same-day PD symptoms. Despite moderate between-person correlations (rrange = .28-.41) between invalidation and minority stress measures, they were more modestly associated on a within-person basis (rrange = .09-.11). In a multilevel multiple regression model, both invalidation and minority stress uniquely predicted daily PD symptoms, collectively accounting for approximately 20% of within-person outcome variation. Based on these results, we speculate that various forms of invalidation (i.e., those that target thoughts, emotions, self-concepts, and identities) interact with PD features in a vicious cycle, such that daily invalidation activates personality pathology, which evokes more invalidation, and so on. We encourage more recognition of identity-based invalidation and investigation into the ways that minority stress could advance interpersonal theories of personality pathology. (PsycInfo Database Record (c) 2025 APA, all rights reserved).