This article reviewed 47 methodological publications critically evaluating ambulatory assessments (AA), network analyses (NA), and single-case experimental designs (SCED) for psychotherapy research and practice. To develop a consensus about the most essential advances and challenges, we invited methodological and clinical experts to participate in a subsequent Delphi study. The experts agreed upon 17 essential advances (e.g., AA particularly disentangles within-and between-psychological processes; NA improves the conceptualization of interacting symptoms, and SCED provides a promising tool for initial proof-of-principle studies). They agreed upon 10 major challenges (e.g., to provide standardized, clear-cut recommendations and userfriendly tools). We discuss how future research could combine rigorous sampling schemes (AA) with a more holistic view on interacting symptoms (NA) and/or a systematic experimental manipulation (SCED).
Public Health Significance StatementWe reviewed and evaluated major advancements and challenges of new research methods for psychotherapy research and practice: Ambulatory assessments disentangle within-and between-psychological processes; network analyses are valuable for conceptualizing interacting symptoms; singlecase experimental designs are a promising tool for providing initial proof of principles. Future research urgently needs to provide clear-cut recommendations and user-friendly tools to contribute to the further dissemination of these methods.