What criteria is being used to reference great minds of history to mental illness?

Are we basing this on historical documentation of their erratic behavior? I have often heard Van Gogh, and Poe referred to as manic depressive/schizophrenic/ect. Albert Einstein as autistic/schizophrenic among numerous other dead greats now being diagnosed. Did we establish these assumptions to bring consolation to those suffering from mental illness, or in our pretentious faith [...] http://bit.ly/o3OJz6