Psychiatry is the branch of medicine that deals with the diagnosis, study, prevention and treatment of mental disorders in humans and, like other fields of science, is not safe from unfounded criticism or woo. It is particularly hated by Scientologists, who refrain from taking psychiatric drugs, and is targeted by conspiracy theories
cult religion. Due to its checkered past and controversial practices like involuntary treatment, use of physical restraints, and procedures like lobotomy and electroconvulsive therapy (all of which except lobotomy are still in use), psychiatry has garnered a significant amount of academic and folk opposition, known as anti-psychiatry.
Psychiatry and psychology
Psychiatry as a profession should not be confused with clinical or counselling psychology, which is closely related. Although much of their respective practices overlap with each other, psychiatrists differ from psychologists in that they have medical training and are licensed to prescribe medications and order lab tests. Psychologists, by comparison, have an advanced degree in psychology (most often a Ph.D. or a PsD.) and use a non-medical approach involving talk therapy and psychological testing.
Early and modern psychiatry
Interestingly enough, early psychiatry involved purging Satan from patients, and today religion is still relevant. People who believe in an angry, punishing God are more likely to suffer psychiatric symptoms than people without that belief. Even earlier than purging Satan, holes were drilled into the skull.
In the 19th century, psychiatrists diagnosed young men with mental illness based on the fact that they masturbated. Masturbation was thought to rob 'vital forces' from the body, and potentially cause insanity. "Sexual neurosis" was diagnosed in younger men and was said to be caused by masturbation. Canadian physician Stephen Lett stated
“”“in early life, the child who thus pollutes himself [with masturbation] retards and arrests the healthy development of his nervous system, and the practice in such a one tends to idiocy and imbecility.”
During most of the 20th century, psychiatry was dominated by the psychoanalytic school started by Sigmund Freud and developed in non-Freudian directions by Carl Jung and Alfred Adler and others. This has since fallen out of favour. These days, psychiatrists tend to prefer treatments such as newer forms of psychotherapy and pharmaceuticals like antidepressants (although the efficacy of these has been called into question from time to time). Psychiatrists treat a wide variety of "conditions" that don't have any reliable blood tests (or the like) ranging from phobias to personality disorders, autism, gender dysphoria, PTSD and schizophrenia. In some cases their subject matter overlaps with that of neurology, such as various forms of dementia, brain injury and sleep disorders like sleep paralysis. Many of the first psychiatrists were in fact trained as neurologists, including Freud.
In the United States, the American Psychiatric Association's official handbook, the DSM (now in its 5th edition) is meant to be a universal guide to psychiatric diagnosis using standardized criteria. Any revisions to the DSM are generally met with controversy over the validity of its categories and whether certain disorders are real diseases versus social constructs. Particularly due to the frequency and lack of consensus of how mental "diseases" should be introduced or removed. The criteria for medicalizing mental states has been reported as undefinable by the lead editor of the DSM-IV:
There is no definition of a mental disorder. It’s bullshit. I mean, you just can’t define it.”—Allen Frances, lead editor of the fourth edition of the American Psychiatric Association’s Diagnostic and Statistical Manual of Mental Disorders
Perhaps lending to the idea that mental illnesses are social constructs, public pressure has led to the institutional exclusion of "conditions" seriously considered by professionals to be disorders, including but not limited to homosexuality, neurosis, and "late luteal phase dysphoric disorder". Because psychiatric disorders are diagnosed by matching patient-reported symptoms and whole-body observation to simple checklists rather than biological testing with biomarkers, it is not uncommon for people to self-diagnose through a combination of their own opinion and their friends. People who sunk hundreds of thousands of dollars into pseudoscience in an academy in their late teens tend to look down on this sort of thing, however.