Madhouse (2004)

Psychiatric intern Clark Stevens comes to Cunningham Hall, a mental-health facility administrated by Dr. Franks, for a training period before his graduation from medical school. He gets close to resident Sara and to Ben London, a dangerous patient lodged in cell 44 in the clinic's basement. He becomes intrigued with a boy who seems to be a ghost, then discovers that the patients receive no real medication. A further investigation shows hidden dark secrets in the clinic.