This temporal proximity ensured that the validity of the A-TAC screening could be assessed with high precision against clinical realities. Quantitative psychometric analyses revealed that the A-TAC possesses strong screening potential to discriminate children with clinically diagnosed neurodevelopmental disorders from control participants. From a research perspective, the validation of A-TAC against robust clinical diagnoses enriches the epidemiological toolkit available for studying neurodevelopmental disorders. Article Title: Thorough clinical child psychiatric diagnostic evaluation and validation of the Autism- Tics, ADHD and other comorbidities inventory (A-TAC) in a population-based sample of 9-year-olds. Thorough clinical child psychiatric diagnostic evaluation and validation of the Autism- Tics, ADHD and other comorbidities inventory (A-TAC) in a population-based sample of 9-year-olds.