A psychiatric hospital is a hospital specialising in the treatment of persons with mental illness. Psychiatric wards differ only in that they are a unit of a larger hospital.Psychiatric hospitals have a number of differences from other hospitals. First, they often have elaborate procedures to prevent patient suicide (for example, appliances with power cords are not allowed, and access to stairways and high, open windows is restricted. Second, they attempt to reduce the amount of sensory stimulation patients receive. Contrary to popular belief, psychiatric hospitals are generally quiet, even boring places. Third, psychiatric hospitals often try to as normal an environment as possible. For example, unlike most other hospitals many or most patients in psychiatric hospitals wear everyday clothes rather than patient examination garments.

In the United States, psychiatric hospitals in the past were often set up as separate institutions with funding and administrations separate from those of general health care. Since the development effective therapies in the there has been an increasing move towards integration of psychiatric treatment within the general health sector. Psychiatric wards in general hospitals and various based treatments are replacing the old asylums worldwide.

In the United Kingdom during the late county authorities were expected to provide their own asylums, for the care or incarceration of lunatics. Private institutions had existed before this, and provided the only care available. Throughout this period, private institutions continued to exist and be founded for so called idiots and imbeciles, who were usually those who today would be said to have mental retardation or learning disabilities. The county asylum structure was nationalised in when the institutions were absorbed into to the and worldwide, most psychiatric hospitals have been replaced by Care in the Community and psychiatric wards in general hospitals. It was only until relatively recently that incarceration was mandatory for all with considerable mental health problems. Today, secure and medium-secure units care for those who require more support or supervision.

Today, in both countries, if a patient had been admitted to the hospital on a voluntary basis, the patient is often allowed to check him or herself out of the hospital against medical advice. In most jurisdictions, requires at least a day's notice. This is so in the event a doctor decides the patient would still present a danger to self or others, there is time to commence involuntary commitment procedures.Since the efforts have been made to improve mental health care. Nevertheless, many problems remain in those countries where free health not available or where funding is limited. This especially affects those with little money to pay for expensive facilities. Limited funding of hospitals can lead to a lack of adequate staff and resources which can lead to the use of restraints and medication for punishment rather than treatment. Procedural deficiencies such as a lack of documentation for involuntary treatment and other serious deficiencies remain all too common in some countries.

The history of psychiatric hospitals is linked heavily with social and scientific attitudes towards mental health, and the attitudes towards those afflicted with mental illness, both of which have changed greatly over the past centuries.Scene of Bethlem Hospital from the final plate of William Hogarth's A Rake's Progress.As the number of people living in cities increased, there became an increasingly large population of urban mentally ill. Generally speaking, in rural areas the mentally ill had been able to rely on local charity and support, managed to simply "blend in" with the rest of the population. However, under the demands of larger cities they faced a higher degree of difficulty and had a much greater chance of causing disruption or simply being noticed. This led to the building early asylums which were little more than repositories for the mentally ill – removing them from mainstream society in the same manner as a jail would for criminals. Conditions were often extremely poor and serious treatment was not yet an option. The first known psychiatric hospital, Bethlem Royal Hospital was founded in London in had begun accepting "lunatics". It soon became famous for its harsh treatment of the insane and in the 18th century would allow visitors to pay a penny to observe their patients as a form of "freak show". In it is recorded that the "lunatics" were called "patients" for the first time, and within twenty years separate wards for the "curable" and "incurable" patients had been established, representing the beginning of a clear shift in the attitude towards mental illness towards a disease of some form.

In 1793 Phillipe Pinel is credited as being the first to introduce humane methods into the treatment of the mentally ill as the superintendent of the Asylum de Bicêtre in Paris. He removed patient restraints and introduced categorising and separation as well as observation and talking to patients as methods of cure. At much the same time William Tuke was pioneering a more enlightened approach to the treatment of the mentally ill in England. These ideas gradually took hold in different countries, and in the United States attitudes towards the treatment of the mentally ill began to drastically improve during the mid-Dix in the United States, began to advocate a more humane and progressive attitude towards the mentally ill. In the United States, for example, numerous states established state mental health systems paid for by taxpayer money d often money from the relatives of those institutionalised These centralised institutions were often linked with loose governmental bodies, though in general oversight was not high and quality consequently varied. They were generally geographically isolated as well, located away from urban areas because the land was cheap and there was less political opposition. Many state hospitals in the United States were built in the on the Kirkbride Plan, an architectural style meant to have curative effect.

While many of those in state hospitals were voluntarily admitted, many more were involuntarily committed by courts. For this reason, state hospital patients were usually from the lower class, as the mentally ill from families with money often had enough private care to avoid being labelled a public menace.In the , state hospitals in some places began to overflow by the beginning of the . As state populations increased, so did the number of mentally ill and so did the cost of housing them in centralised institutions. During wartime, state mental hospitals became even more overburdened, often serving as hospitals for returning servicemen as well as for their regular clientele. The incentive to discharge patients was high, yet there were still no adequate treatments or therapies for the mentally ill.

Stockton State Hospital, in Stockton, California, was California's first state psychiatric hospital (picture ca. 1910).This provided a fruitful environment for the popularity of quick-fix solutions, like the eugenic compulsory sterilisation programs undertaken in over 30 U.S. states (and, later, in Nazi Germany), which allowed institutions to discharge patients while still claiming to be serving the public interest. These new treatments of mental illness – which was now seen as a "defect", and likely a hereditary one – were seen less as therapeutic for the individual patient than as preventative for the society as a whole.By th treatment of the mentally ill became effective for the first time with the advent of electroconvulsive therapy (ECT) and insulin shock therapy, and the use of the lobotomy technique. In modern times, insulin shock therapy and lobotomies are viewed as being almost as barbaric as the Bedlam "treatments", though in their own copt to aid those suffering from early signs of mental illness before they got to the stage where they would be institutionalised in a mental hospital. At the time, mental hospitals were viewed as the least desirable solution to the problem of mental illness, both from a humane point of view and an economic one. The point of view continued to promulgate and went even further in the backlash against social welfare policies in the 1980s, which lead to massive deinstitutionalisation and funding cuts. These changes lead to the closing of many mental hospitals and the further reliance on local community care.

In some nations, mental hospitals were used as sites for the stifling of political dissidence or even genocide. Under Nazi Germany, a euthanasia program began which resulted in the killings of tens of thousands of the mentally ill housed in state institutions, and the killing techniques perfected at these sites became later implemented in the Holocaust (see T-4 Euthanasia Program). In the Soviet Union, dissidents were often put into asylums and kept on a variety of destabilising medications, with the hope of not simply removing them from society, but making them unreliable in the eyes of others (see Psikhushka). Both of the attitudes in these cases – that the mentally ill were a scourge and needed to be eliminated, and that the line between 'patient' and 'prisoner' is incredibly blurry – have their precedents in the history of mental hospitals, though were taken to extremes by totalitarian regimes.

Mental hospitals in the media
Mental hospitals are often depicted as frightening places in fiction, where treatments are forced upon inmates by uncaring staff, or inmates themselves are either violently deranged or sinister. Although there have been cases of abuse of patients in real life, and some conditions do occasionally result in violent behaviour, this stereotype of mental hospitals is grossly misleading.Some recent depictions of mental hospitals in the media include:

K-Pax, a film starring Kevin Spacey as an instituti who claims to be a space alien.
AAsylum, in the Batman mythos. In the films, the asylum was seen briefly in Batman Forever and then in Batman and Robin, but had a more vital role in Batman Begins. Girl, Interrupted, a film based on a book written by a former patient of McLean Hospital a film in which Halle Berry plays a psychiatrist who ends up institutionalised in the very hospital she used to work at.
In Halloween, after having murdered his sister, a young Michael Myers is placed in Smith's Grove Sanitarium until he escapes 15 years later.
House on Haunted Hill set in The Vannacutt Psychiatric Institute for the Criminally Insane, a fictional institute reknown for its mass-murdererings of patients in Los Angeles, CA.
One Flew Over the Cuckoo's Nest, a film based on a book by Ken Kesey about power and identity, set in a brutally-run mental institution.
Patch Adams, a film starring Robin Williams as "Patch" Adams, a man who checks himself into a mental hospital but eventually leaves when he discovers what he needs isn't there.
Session 9, a film shot in Danvers State Hospital in which a cleaning crew wins a bidding contract to clean up an abandoned large mental hospital within a week. One of the cleaners discovers old tapes of disturbing therapy sessions and develops schizophrenia under the stress of the tight schedule. Sharon's Secret, a film about an institutional psychiatrist investigating a 16-year-old girl suspected of murdering her parents.
Terminator 2: Judgment Day, an action film in which Linda Hamilton plays a heroine committed for her (apparently) delusory belief that the end of the world is about to be brought about by a killer artificial intelligence.
In The Silence of the Lambs, Dr Hannibal Lecter is held at the Baltimore State Hospital for the Criminally Insane.
Twelve Monkeys, a science fiction film in which a man claiming to be from a post-apocalyptic future (played by Bruce Willis) understandably ends up being committed.

Ginger Snaps 2: Unleashed, a horror flick in which Emily Perkins plays a young werewolf who is committed to mental institution after overdosing on an anti-lycantropic serum intended to cue German army. The town's insane asylum is accidentally unlocked as the Germans are leaving and the inmates take over the town.

The Simpsons television series features Calmwood Mental Hospital is several episodes, most notably "Hurricane Neddy", in which Ned Flanders—whose home had been destroyed in a hurricane—checks in after thinking he's lost his mind.
Psychonauts Pointy Towers Home for the Disturbed is the laboratory of the evil Dr. Loboto. Raz infiltrates the decrepit mental hospital (at night, mind you) to rescue his girlfriend Lilli from the Doctor's clutches.