Neurosis (plural: neuroses) is a term mainly used today by followers of Freudian thinking to describe mental disorders caused by past anxiety, often that has been repressed. This concept is more usually known today as psychological trauma. In recent history, the term has also referred to anxiety-related conditions more generally. Sublimation can be considered neuroses' positive counterpart. Neurosis should not be mistaken for psychosis, which refers to a loss of touch with reality. Nor should it be mistaken for its descendant term neuroticism, which refers to a personality trait of being prone to anxiousness and mental collapse. History The term is derived from the Greek word neuron (νεῦρον, 'nerve') and the suffix -osis (-ωσις, 'diseased' or 'abnormal condition'). The term neurosis was coined by Scottish doctor William Cullen in 1769 to refer to "disorders of sense and motion" caused by a "general affection of the nervous system." Cullen used the term to describe various nervous disorders and symptoms that could not be explained physiologically. Physical features, however, were almost inevitably present, and physical diagnostic tests, such as exaggerated knee-jerks, loss of the gag reflex and dermatographia, were used into the 20th century. French psychiatrist Pierre Janet believed that the main aspect of psychological trauma is dissociation (a disconnection of the conscious mind from reality) in 1889. (Freud would later claim Janet as a major influence.) In the 1890s, after working with Janet, French neurologist Jean-Martin Charcot argued that psychological trauma was the origin of all instances of the mental illness known as hysteria. Austrian psychiatrist Sigmund Freud was a student of Charcot in 1885-6. Freud was also mentored by Austrian psychiatrist Josef Breuer. Breuer and Freud wrote Studies on Hysteria (1895) together, which established the field of psychoanalysis. The book included five case studies, the most famous becoming that of Breuer's patient "Anna O." Freud developed a number of different theories of neurosis. The most impactful one was that it referred to mental disorders caused by the brain's defence against past psychological trauma. This redefined the general understanding and use of the word. It came to replace the concept of "hysteria." Freud's most important work on the topic was his lectures later grouped together as "General Theory of the Neuroses" (1916–17), forming part 3 of the book Introduction to Psychoanalysis (1923). In that work, Freud noted that:The meaning of neurotic symptoms was first discovered by J. Breuer in the study