I see that the database includes a Participant Stage across all phases (ADNI1/GO/2) where is this dataset? How do I link RID (ID) to participant stage? More directly, I am lookng for a list of the controls. Thanks!
If you are looking for diagnosis information, download the Diagnostic Summary file from the Study Data page (where you can download all of the ADNI data files). You can use RID to link between files.