McLean Hospital (/məkˈleɪn/) (formerly known as Somerville Asylum and Charlestown Asylum) is a psychiatric hospital in Belmont, Massachusetts. It is noted for its clinical staff expertise and neuroscience research and is also known for the large number of famous people who have been treated there. McLean maintains the world's largest neuroscientific and psychiatric research program in a private hospital. It is the largest psychiatric facility of Harvard Medical School, an affiliate of Massachusetts General Hospital, and part of Mass General Brigham, which also includes Brigham and Women's Hospital.