Level of evidence Direct evidence from analysing biosamples in two child cohorts – Walnuts (Spain) and FinnTwin (Finland) Approach Preliminary biomarker discovery in the Walnuts cohort: ·      We analysed plasma proteomic and bioinformatic data and identified significant changes in several proteins by comparing low- and high-risk groups, based on SDQ scores. (de Sousa Maciel et al. 2023). ·      We carried out further analyses for the entire sample set of 198 Walnuts plasma u