The report provides valuable insights from a cross-disciplinary group of leading researchers and stakeholders within brain-related disorders, with a focus on five main topics: 1) Legal, Ethical, and Societal Compliance, 2) Data Acquisition, 3) FAIR Data, 4) Models Needed for Patient Assessment, and 5) Innovation and Science Needs. The report offers a detailed roadmap to achieve the vision of improving the investigation of brain-related disorders. The results are based on careful deliberation between researchers, experts, and stakeholders following the EBRAINS CoCreate framework. EBRAINS CoCreate builds upon the method of Open Research Agenda Setting (ORAS), which recognises the benefits of engaging multiple actors in defining future research. The resulting research agendas include visions and actions that a variety of actors find important, thereby strengthening and legitimising the selection of research priorities. The EBRAINS CoCreate Improved Investigation of Brain-Related Disorders process comprised five workshop sessions arranged from February 2023 to March 2023, with the first and last workshops conducted online and the three-day workshop held in Copenhagen, Denmark. The report first takes the reader through a narrative to set the scene for the envisioned future. Thereafter, the roadmap with actions required to achieve the vision for improving the investigation of brain-related disorders is visualised and then elaborated upon with detailed descriptions of the actions. Finally, the report also highlights recommendations from the participants to demonstrate how EBRAINS can be a vital player in realising the roadmap and how the vision can be realised today.