McLean Hospital (/m?k'le?n/) — formerly known as Somerville Asylum and Charlestown Asylum — is a psychiatric hospital in Belmont, Massachusetts, USA. McLean is noted for its clinical staff expertise and ground-breaking neuroscience research. It is also known for the large number of famous people who have been treated there, including mathematician John Nash, singer-songwriters James Taylor and Ray Charles, poets Sylvia Plath, Robert Lowell, and Anne Sexton, and authors Susanna Kaysen and David Foster Wallace. McLean maintains the worlds 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 owned by Partners HealthCare, which also owns Brigham and Womens Hospital.