Self-Stigma Is Not a Monolith, but Generic Empathy Is: Persona-Conditioned LLM Support for People Who Use Drugs

Persona-conditioned LLM support for people who use drugs reveals tension between generic empathy and clinical alignment

Researchers present a proof-of-concept study using Latent Profile Analysis on Reddit data to identify four self-stigma personas among people who use drugs, then train classifiers to detect these personas from posting history (macro-F1 = 0.74 at 30 posts). Persona-matched LLM responses achieved targeted behavioral shifts, but clinical expert raters preferred the generic empathy of persona-neutral baselines. The core finding is a misalignment: holistic empathy judgments and clinically-aligned response design can pull in opposite directions, suggesting current evaluation rubrics for LLM-based mental health support are inadequate.