Aarhus University (AU) has 43,600 students; about 1,900 PhD students - of which one in four has a foreign nationality - and close to 700 postdoctoral scholars together with 11,000 employees. In recent years AU has been moving up the most important university ranking lists. In 2014 the university was number 68 at the Leiden Ranking, and number 138 of 17,000 universities on the Times Higher Education World University Ranking (2013). AU has participated in 278 FP7 projects. It has hosted/is currently hosting 29 ERC projects and 69 Marie Curie projects both Fellowships and Initial Training Networks. AU therefore has a very successful track record of managing both individual fellowships and large international projects and of hosting visiting researchers of all career stages for both training and knowledge transfer purposes. Internationalisation is part of the University’s mission and it continuously works to strengthen the international profile of the University through a series of initiatives, which will increase international research partnerships and the number of international students. The AU group will participate in several WPs (WP2, 3, 4, 7, 9) of the proposal, contributing large data sets, excellent infrastructure, and recognized expertise in the research fields of the WPs. In particular, the AU team has renowned expertise in psychiatric genetics, psychiatric epidemiology, genetic epidemiology, molecular genetics, and register-based research, all key areas of the present proposal. Important resources include GWAS data from a total population birth cohort comprising more than 80,0000 genotyped individuals, including approximately 18,000 ADHD cases with information on a long range of comorbidities, outcomes, and environmental exposures, a large high performance computer platform dedicated to genomics and related bioinformatics, as well as a wealth of longitudinal, individual data on a total population scale through the comprehensive Danish register system.