Equus was written in 1973, a time when many advancements were being made in the field of psychiatry, but much was still left to be uncovered. In the early 20th century, a technique called psychoanalysis prevailed among psychiatrists, pioneered by the famous psychologist Sigmund Freud. Psychoanalysis stood by a few key tenants in mental illness; notably, that a person's development is determined by events in early childhood, and that many human thoughts and mannerisms are controlled by the unconscious mind.
Beginning in the 1960s, however, people began to question the legitimacy of many of Freud's theories and techniques. Critics claimed psychoanalysis had very little basis in substantive scientific research. Many also believed that current psychiatric techniques—including things like electric shock therapy and lobotomies—were too dangerous, and did more harm than good.
This spawned the anti-psychiatry movement, which was officially given its name in 1967, when South African psychiatrist coined the term "anti-psychiatry." Psychiatrists were criticized for their practices; in particular, mental institutions were condemned for their involuntary commitment and treatment of patients.
This fear was particularly prominent in the late 60s into the early 70s, and elements of it still remain in contemporary society. Since psychiatry is an ever-evolving field and there is still so much left to uncover about the human mind, there is still much controversy about the definition of mental illness, what should be considered mental disorders, and how to treat these ailments.
Today, certain types of treatment are used as an alternative to psychiatry, including family therapy, counseling, and self-help. Many proponents of these types of therapies over psychiatry insist that drugs and medicine are not the most effective ways to treat mental disorders.