2025-03-102026-03-272025-03-1020241050-330710.1080/10503307.2023.2239448https://doi.org/10.1080/10503307.2023.2239448https://repositorio.inprf.gob.mx/handle/123456789/8234Objective: Develop and obtain content validity of a new tool for Evaluating and Classifying the Severity of Adverse Events for Psychotherapeutic Clinical Trials (EVAD). Method: Study of the development process of EVAD in four stages: (1) identify the domain and concept definition through a literature review, (2) instrument design, (3) expert judgment of the EVAD items through Gwent's concordance coefficient, and (4) applicability. Results: In the absence of a consistent conceptual framework of adverse events in psychotherapeutic clinical trials, we have developed a framework and defined it. We have designed EVAD items and their complementary tool for rating adverse events. Content validation by expert judges resulted in CVR = 1.0 for each item and CVI = 0.79 in sufficiency, 0.76 in clarity, 0.91 in coherence and 0.95 in relevance for all items (p < 0.001). Final version of EVAD were applied to three participants for 7 weeks. Overall EVAD seems to be clear and meaningful for participants. Conclusions: EVAD is a semistructured interview based on a consistent conceptual framework, and proven content validity following the most important guidelines described in the literature. Trial registration: ClinicalTrials.gov identifier: NCT03878186.PDFengAcceso CerradoArtículo1468-4381Instituto Nacional de Psiquiatría Ramón de la Fuente MuñizInglaterraAdverse eventsEvaluationPsychotherapyClinical trialsPatient safetyFramework