A history of neurosis is mostly a history of the symptoms associated with sexual abstinence or unfulfillment, e.g. chronic muscular tension, shortness of breath, tachycardia, and
emotional instability - and these, predominantly in women. Around 420 BC, the Greek medical philosopher
Hippocrates supposed that these complaints were caused by the
uterus literally wandering the body in its restless urge to get fertilized and produce offspring - hence "
hysteria" (Greek "hyster", uterus).
The term "neurosis" originated in 1776, with the Scottish doctor William Cullen, in his publication "First Line in the Practice of Medicine". He supposed that hysteria and similar disorders were caused by some physical disorder of the nervous system. This was a departure from the prevalent theory of physical disorder of the cardiovascular system.
In the early 1900's, Sigmund Freud and his contemporaries essentially redefined "neurosis" to refer to psychological disorders with no physical origin - although they might produce physical (i.e. psychosomatic) symptoms, such as numbness, hypersensitivity, muscular tension, or organ dysfunction. The popular explanation was that neuroses such as hysteria were caused by anxiety, arising from urges so repressed as to become unconscious. Meanwhile, shell-shocked veterans returning home from World War I provided ample opportunity for psychologists to examine neurosis in males. Up to then, neurosis had been considered primarily a "female problem", even a sign of intrinsic female weakness or inferiority. Neurotic males had often been viewed as effeminate, when their neurotic symptoms weren't altogether misdiagnosed as moral failure or physical illness.
Under Freud's model, hysterical neurosis was seen as a symptom of anxious inner conflict between the sex drive and society's harsh disapproval of masturbation and premarital sex, perhaps reinforced by repressed early childhood memories of punishment for sexual behavior. Likewise, a child punished for crying might develop a facial tic or chronic tension headaches, in addition to losing the ability to empathize with sadness and frustration in others. An infant weaned too early might develop neurotic habits associated with the "oral personality". The cure involved revealing the unconscious, repressed urges and early childhood punishment or deprivation memories, so that the patient might begin coping rationally.
As the incredibility of some of Freud's theories1 shadowed the rest of his work, the term "neurosis" came to be applied generally to those psychological disorders where the patient was still quite in touch with consensus reality. Neurosis then became a point on a spectrum model of mental health, starting with an ideal of "total health", shading through neurosis, to "borderline", and ending at psychosis, in which the patient is subject to delusions and hallucinations (out of touch with consensus reality).
As of the publication of the DSM-IIIR, the neurosis/psychosis terminology was officially deprecated, although it remains widespread in informal use.
1. E.g. the supposed immaturity of clitoral orgasm, or the "latency stage" of psychosexual development. Bronislaw Malinowski's documentation of child sexuality in "The Sexual Life of Savages" undercut the theory of a psychosexual dormancy, and sexology has long deprecated Freud's notion that women who can orgasm only with clitoral stimulation are somehow necessarily "immature".