We feel that it would be very timely to present a symposium on these studies at OHBM, to give visibility to what brain imaging is being done, and how it relates (in different ways in the different studies) to these healthcare/epidemiology studies more broadly. We will present “early” results (including from brain imaging of over 10,000 subjects already!), including associations between the neuroimaging data and other healthcare and lifestyle variables. We also include a presentation covering many complex and challenging methodological issues in such large-scale studies.