A report by the Agency for Healthcare Research and Quality shows that almost one fourth of about 32 million stays in 2004 in US community hospitals for adult patients involved such mental health disorders as depression, bipolar disorder, and schizophrenia or substance abuse–related disorders.
About 1.9 million of the stays were for patients who were hospitalized primarily because of a mental health or substance abuse problem. In the other 5.7 million stays, patients were admitted for another condition but were also diagnosed as having a mental health or substance abuse disorder.
Hampton T. Mental Health of Inpatients. JAMA. 2007;297(20):2188. doi:10.1001/jama.297.20.2188-d