In Europe, 10-15% of children and adults or 50 to 75 million individuals are affected by neurodevelopmental conditions, such as autism, attention-deficit hyperactivity disorder (ADHD), intellectual disability (ID), motor problems and language disorders. It is not hard to imagine that one of these conditions alone can have a serious impact on a person’s life. What makes the situation even worse is the fact that several of these conditions often co-exist and, on top of that, go along with somatic illnesses, such as epilepsy. This significantly affects both life expectancy and quality of life and there are no effective treatments to date. In the CANDY project, we investigate the biological links between these neurodevelopmental conditions and co-existing somatic illnesses and how treatment and monitoring of affected patients can be improved.