Hospital specializing in the treatment of serious mental disorders
A psychiatric hospital, also known as a mental health hospital, a behavioral health hospital, or an asylum is a specialized medical facility that focuses on the treatment of severe mental disorders. These institutions cater to patients with conditions such as schizophrenia, bipolar disorder, major depressive disorder, and eating disorders, among others.
Overview.
Psychiatric hospitals vary considerably in size and classification. Some specialize in short-term or outpatient therapy for low-risk patients, while others provide long-term care for individuals requiring routine assistance or a controlled environment due to their psychiatric condition. Patients may choose voluntary commitment, but those deemed to pose a significant danger to themselves or others may be subject to involuntary commitment and treatment. 
In general hospitals, psychiatric wards or units serve a similar purpose. Modern psychiatric hospitals have evolved from the older concept of lunatic asylums, shifting focus from mere containment and restraint to evidence-based treatments that aim to help patients function in society. Drug administration, as well as structured and one-to-one therapy (such as occupational therapy and psychotherapy) play a role in trajectories. They are the focus of most studies on forms of treatment that exist in psychiatric wards. However, because psychiatric wards are social living spaces, inpatient relationships in psychiatric wards also play a role in survival and recovery trajectories.
With successive waves of reform, and the introduction of effective evidence-based treatments, most modern psychiatric hospitals emphasize treatment, usually including a combination of psychiatric medications and psychotherapy, that assist patients in functioning in the outside world. Many countries have prohibited the use of physical restraints on patients, which includes tying psychiatric patients to their beds for days or even months at a time, though this practice still is periodically employed in the United States, India, Japan, and other countries.
History.
Modern psychiatric hospitals evolved from, and eventually replaced, the older lunatic asylum. Their development also entails the rise of organized institutional psychiatry.
Hospitals known as bimaristans were built in the Middle East in the early ninth century; the first was built in Baghdad under the leadership of Harun al-Rashid. While not devoted solely to patients with psychiatric disorders, early psychiatric hospitals often contained wards for patients exhibiting mania or other psychological distress.
Because of cultural taboos against refusing to care for one's family members, mentally ill patients would be surrendered to a "bimaristan" only if the patient demonstrated violence, incurable chronic illness, or some other extremely debilitating ailment. Psychological wards were typically enclosed by iron bars owing to the aggression of some of the patients.
In Western Europe, the first idea and set up for a proper mental hospital entered through Spain. A member of the Mercedarian Order named Juan Gilaberto Jofré traveled frequently to Islamic countries and observed several institutions that confined the insane. He proposed the founding of an institution exclusive for "sick people who had to be treated by doctors", something very modern for the time. The foundation was carried out in 1409 thanks to several wealthy men from Valencia who contributed funds for its completion. It was considered the first institution in the world at that time specialized in the treatment of mental illnesses.
Later on, physicians, including Philippe Pinel at Bicêtre Hospital in France and William Tuke at York Retreat in England, began to advocate for the viewing of mental illness as a disorder that required compassionate treatment that would aid in the rehabilitation of the victim. In the Western world, the arrival of institutionalisation as a solution to the problem of madness was very much an advent of the nineteenth century. The first public mental asylums were established in Britain; the passing of the County Asylums Act 1808 empowered magistrates to build rate-supported asylums in every county to house the many 'pauper lunatics'. Nine counties first applied, the first public asylum opening in 1812 in Nottinghamshire. In 1828, the newly appointed Commissioners in Lunacy were empowered to license and supervise private asylums. The Lunacy Act 1845 made the construction of asylums in every county compulsory with regular inspections on behalf of the Home Secretary, and required asylums to have written regulations and a resident physician.
At the beginning of the 19th century there were a few thousand people housed in a variety of disparate institutions throughout England, but by 1900 that figure had grown to about 100,000. This growth coincided with the growth of alienism, later known as psychiatry, as a medical specialism. The treatment of inmates in early lunatic asylums was sometimes very brutal and focused on containment and restraint.
In the late 19th and early 20th centuries, psychiatric institutions ceased using terms such as "madness", "lunacy" or "insanity", which assumed a unitary psychosis, and began instead splitting into numerous mental diseases, including catatonia, melancholia, and dementia praecox, which is now known as schizophrenia.
In 1961, sociologist Erving Goffman described a theory of the "total institution" and the process by which it takes efforts to maintain predictable and regular behavior on the part of both "guard" and "captor", suggesting that many of the features of such institutions serve the ritual function of ensuring that both classes of people know their function and social role, in other words of "institutionalizing" them. Asylums as a key text in the development of deinstitutionalization.
With successive waves of reform and the introduction of effective evidence-based treatments, modern psychiatric hospitals provide a primary emphasis on treatment; and further, they attempt—where possible—to help patients control their own lives in the outside world with the use of a combination of psychiatric drugs and psychotherapy. These treatments can be involuntary. Involuntary treatments are among the many psychiatric practices which are questioned by the mental patient liberation movement.
In America history in the 1980s after the "12,225,000 Acre Bill" it was emphasized that care would be given in asylums instead of housing the individuals in jails, poorhouses, or having them live on the streets. Due to the decrease over the years of psychiatric hospitals available depending on the state the availability of space and beds for new patients has drastically decreased. 
Types.
There are several different types of modern psychiatric hospitals, but all of them house people with mental illnesses of varying severity. In the United Kingdom, both crisis admissions and medium-term care are usually provided on acute admissions wards. Juvenile or youth wards in psychiatric hospitals or psychiatric wards are set aside for children or youth with mental illness. Long-term care facilities have the goal of treatment and rehabilitation within a short time-frame (two or three years). Another institution for the mentally ill is a community-based halfway house.
Crisis stabilization.
In the United States, there are high acuity and low acuity crisis facilities (or Crisis Stabilization Units). High acuity crisis stabilization units serve individuals who are actively suicidal, violent, or intoxicated. Low acuity crisis facilities include peer respites, social detoxes, and other programs to serve individuals who are not actively suicidal/violent. 
Open units.
Open psychiatric units are not as secure as crisis stabilization units. They are not used for acutely suicidal people; instead, the focus in these units is to make life as normal as possible for patients while continuing treatment to the point where they can be discharged. However, patients are usually still not allowed to hold their own medications in their rooms because of the risk of an impulsive overdose. While some open units are physically unlocked, other open units still use locked entrances and exits, depending on the type of patients admitted.
Medium term.
Another type of psychiatric hospital is medium term, which provides care lasting several weeks. Most drugs used for psychiatric purposes take several weeks to take effect, and the main purpose of these hospitals is to monitor the patient for the first few weeks of therapy to ensure the treatment is effective.
Juvenile wards.
Juvenile wards are sections of psychiatric hospitals or psychiatric wards set aside for children with mental illness. However, there are a number of institutions specializing only in the treatment of juveniles, particularly when dealing with drug abuse, self-harm, eating disorders, anxiety, depression or other mental illnesses.
As of 2020, the statistics of mental illness among inmates in jails and juvenile wards range from 15% to 20%. Because of this, many juvenile wards and prisons have opened an inpatient mental health unit within their facility. 
Long-term care facilities.
In the United Kingdom, long-term care facilities are now being replaced with smaller secure units, some within hospitals. Modern buildings, modern security, and being locally situated to help with reintegration into society once medication has stabilized the condition are often features of such units. Examples of this include the Three Bridges Unit at St Bernard's Hospital in West London and the John Munroe Hospital in Staffordshire. These units have the goal of treatment and rehabilitation to allow for transition back into society within a short time-frame, usually lasting two or three years. Not all patients' treatment meets this criterion, however, leading larger hospitals to retain this role.
These hospitals provide stabilization and rehabilitation for those who are actively experiencing uncontrolled symptoms of mental disorders such as depression, bipolar disorders, eating disorders, and so on.
In the United States long-term care facilities are used for individuals with severe and continuous mental health struggles. These types of hospitals provide a different from of care compared to other psychiatric hospitals, this type is designed to provide comprehensive care over an extended period of time, higher level of support and care, as well as heavy monitoring of patients.  Within these facilities the care can be better adapted to best fit each individual patient, this allows for a more patient centered focus on the form of care they are receiving.
Halfway houses.
One type of institution for the mentally ill is a community-based halfway house. These facilities provide assisted living for an extended period of time for patients with mental illnesses, and they often aid in the transition to self-sufficiency. These institutions are considered to be one of the most important parts of a mental health system by many psychiatrists, although some localities lack sufficient funding.
Political imprisonment.
In some countries, the mental institution may be used for the incarceration of political prisoners as a form of punishment. One notable historical example was the use of punitive psychiatry in the Soviet Union and China. 
Like the former Soviet Union and China, Belarus also has used punitive psychiatry toward political opponents and critics of current government in modern times.
Secure units.
In the United Kingdom, criminal courts or the Home Secretary can, under various sections of the Mental Health Act, order the detention of offenders in a psychiatric hospital, but the term "criminally insane" is no longer legally or medically recognized. Secure psychiatric units exist in all regions of the UK for this purpose; in addition, there are a few specialist hospitals which offer treatment with high levels of security. These facilities are divided into three main categories: High, Medium and Low Secure. Although the phrase "Maximum Secure" is often used in the media, there is no such classification. "Local Secure" is a common misnomer for Low Secure units, as patients are often detained there by local criminal courts for psychiatric assessment before sentencing.
Run by the National Health Service, these facilities which provide psychiatric assessments can also provide treatment and accommodation in a safe hospital environment which prevents absconding. Thus there is far less risk of patients harming themselves or others. In Dublin, the Central Mental Hospital performs a similar function.
Community hospital utilization.
Community hospitals across the United States regularly discharge mental health patients, who are then typically referred to out-patient treatment and therapy. A study of community hospital discharge data from 2003 to 2011, however, found that mental health hospitalizations had increased for both children and adults. Compared to other hospital utilization, mental health discharges for children were the lowest while the most rapidly increasing hospitalizations were for adults under 64. Some units have been opened to provide therapeutically enhanced Treatment, a subcategory to the three main hospital unit types.
In the UK, high secure hospitals exist, including Ashworth Hospital in Merseyside, Broadmoor Hospital in Crowthorne, Rampton Secure Hospital in Retford, and the State Hospital in Carstairs, Scotland. In Northern Ireland, the Isle of Man, and the Channel Islands, medium and low secure units exist but high secure units on the UK mainland are used for patients who qualify for the treatment under the Out of Area (Off-Island Placements) Referrals provision of the Mental Health Act 1983. Among the three