Beyond the Diagnosis: A Scoping Review of ICF Implementation in Interventions for Adults with Severe Intellectual Disability (2015–2025)

Abstract: Adults with severe intellectual disability (ID) in day-care and residential services often face "chronicity," where static diagnostic labels fail to capture current functioning. While the WHO's International Classification of Functioning, Disability and Health (ICF) offers a bio-psycho-social alternative to the biomedical model, its operational application in this specific population remains under-documented. The goal of this specific analysis is to map the existing literature from the last decade (2015–2025) regarding the practical use of the ICF framework for planning interventions and measuring outcomes in adults with severe ID. A scoping review was conducted on PsycINFO and PubMed databases using the PCC framework. The search yielded 31 records in total. Following screening, 29 studies were excluded due to a predominant focus on biomedical outcomes, diagnostic validation, or population mismatch. Only 2 studies met the inclusion criteria: Nakayama (2023), utilizing ICF for the childhood-to-adulthood transition planning in complex disabilities, and Talman et al. (2018), using ICF to analyze participation in care plans. The review identifies a critical gap in evidence. Current research prioritizes diagnostic categorization over functional intervention. This scarcity validates the need for new operational models aimed at preventing secondary institutionalization through ICF-based care strategies and approaches.