Advancing research for neurologically diverse populations requires new ways to harmonize mental health data. In this new publication in BMJ Mental Health, R2D2-MH researchers introduce the World Health Organization (WHO) International Classification of Functioning, Disability and Health (ICF) as a framework to align data with contemporary health and disability models. By linking 138 measures from various datasets to the ICF, results show that it can enhance data harmonisation and better capture diversity. This work paves the way to new data harmonisation and research approaches to provide a better support to neurodivergent people and families.