A psychiatric hospital is a place where mentally ill people are kept so they can be treated.
Doctors who work at psychiatric hospitals are called psychiatrists. Usually people choose to be in a psychiatric hospital. Sometimes psychiatrists can put people in hospitals who do not want to be there, because they think the people are dangerous to themselves or other people. A halfway house or group home is a place for patients who have left the psychiatric hospital and are slowly being released into society.
Psychiatric hospitals used to be called lunatic asylums. Earlier asylums like the old Bethlem Royal Hospital in London (nicknamed "Bedlam") were like prisons. Patients received no treatment and were often imprisoned and chained. In the 19th century, new asylums were built. These were designed to be pleasant places with gardens and airy rooms, and later became known as psychiatric hospitals. Although they no longer looked like prisons, patients still had little freedom or hope of leaving. The term institutionalisation means when someone has lived in a hospital (or some other place like a prison) for so long that they cannot cope with living outside of it.
In the middle of the 20th century, new drugs were invented that made it easier to treat mental illness. Governments began to look for ways to care for patients outside of hospitals. They believed it would lead to better care for patients and save money. This is known as deinstitutionalisation. Since the 1970s, many countries have closed large numbers of psychiatric hospitals. Mentally ill patients are now also cared for in local hospitals, small clinics and in their own homes.