Our paper "Generative Experiences for Digital Mental Health Interventions: Evidence from a Randomized Study" will appear at UIST 2026. Preprint: arxiv.org/abs/2604.07558. We introduce generative experience as a new approach for digital interventions: dynamically constructing the personalized experience through which an intervention is enacted. Our system, GUIDE, generates multimodal interaction structure from rubric-guided modular components (e.g., audio, video, timers, reflective questions, breathing exercises). Content and format are composed together at runtime. This is different from traditional personalized support, where the interaction flow is authored in advance, and only the content adapts within it. We ran a preregistered study with 237 participants. GUIDE reduced stress (p = .02) and improved user experience (p = .04) compared to an LLM-based cognitive restructuring control. The flows it produced supported different forms of reflection and action. Grateful to my advisors @EmmaBrunskill and @Diyi_Yang for their guidance on this work, and to my collaborators @MichaelLiut and @mjoerke. I also thank @StanfordKingCtr for supporting this work. We are extending this work in different new directions and happy to chat with anyone interested. #generativeai #digitalmentalhealth