Neurosis is a class of functional mental disorders involving chronic distress but neither delusions nor hallucinations. The term is no longer used by the professional psychiatric community in the United States, having been eliminated from the Diagnostic and Statistical Manual of Mental Disorders in 1980 with the publication of DSM III. It is still used in the ICD-10 Chapter V F40-48.
Neurosis should not be mistaken for psychosis, which refers to a loss of touch with reality. Neither should it be mistaken for neuroticism, a fundamental personality trait proposed in the Big Five personality traits theory.
... anxiety, sadness or depression, anger, irritability, mental confusion, low sense of self-worth, etc., behavioral symptoms such as phobic avoidance, vigilance, impulsive and compulsive acts, lethargy, etc., cognitive problems such as unpleasant or disturbing thoughts, repetition of thoughts and obsession, habitual fantasizing, negativity and cynicism, etc. Interpersonally, neurosis involves dependency, aggressiveness, perfectionism, schizoid isolation, socio-culturally inappropriate behaviors, etc.
Neurosis may be defined simply as a "poor ability to adapt to one's environment, an inability to change one's life patterns, and the inability to develop a richer, more complex, more satisfying personality."
- I have frequently seen people become neurotic when they content themselves with inadequate or wrong answers to the questions of life. (Jung  (1989) p. 140)
- The majority of my patients consisted not of believers but of those who had lost their faith. (Jung  (1989) p. 140)
- [Contemporary man] is blind to the fact that, with all his rationality and efficiency, he is possessed by "powers" that are beyond his control. His gods and demons have not disappeared at all; they have merely got new names. They keep him on the run with restlessness, vague apprehensions, psychological complications, an insatiable need for pills, alcohol, tobacco, food -- and, above all, a large array of neuroses. (Jung (1964) p. 82)
Jung found that the unconscious finds expression primarily through an individual's inferior psychological function, whether it is thinking, feeling, sensation, or intuition. The characteristic effects of a neurosis on the dominant and inferior functions are discussed in Psychological Types.
Jung saw collective neuroses in politics: "Our world is, so to speak, dissociated like a neurotic." (Jung (1964) p. 85)
According to psychoanalytic theory, neuroses may be rooted in ego defense mechanisms, but the two concepts are not synonymous. Defense mechanisms are a normal way of developing and maintaining a consistent sense of self (i.e., an ego). But only those thoughts and behaviors that produce difficulties in one's life should be called neuroses.
In her final book, Neurosis and Human Growth, Karen Horney laid out a complete theory of the origin and dynamics of neurosis. In her theory, neurosis is a distorted way of looking at the world and at oneself, which is determined by compulsive needs rather than by a genuine interest in the world as it is. Horney proposed that neurosis is transmitted to a child from his or her early environment and that there are many ways in which this can occur:
When summarized, they all boil down to the fact that the people in the environment are too wrapped up in their own neuroses to be able to love the child, or even to conceive of him as the particular individual he is; their attitudes toward him are determined by their own neurotic needs and responses.
The child's initial reality is then distorted by his or her parents' needs and pretenses. Growing up with neurotic caretakers, the child quickly becomes insecure and develops basic anxiety. To deal with this anxiety, the child's imagination creates an idealized self-image:
Each person builds up his personal idealized image from the materials of his own special experiences, his earlier fantasies, his particular needs, and also his given faculties. If it were not for the personal character of the image, he would not attain a feeling of identity and unity. He idealizes, to begin with, his particular "solution" of his basic conflict: compliance becomes goodness, love, saintliness; aggressiveness becomes strength, leadership, heroism, omnipotence; aloofness becomes wisdom, self-sufficiency, independence. What--according to his particular solution--appear as shortcomings or flaws are always dimmed out or retouched.
Once he identifies himself with his idealized image, a number of effects follow. He will make claims on others and on life based on the prestige he feels entitled to because of his idealized self-image. He will impose a rigorous set of standards upon himself in order to try to measure up to that image. He will cultivate pride, and with that will come the vulnerabilities associated with pride that lacks any foundation. Finally, he will despise himself for all his limitations. Vicious circles will operate to strengthen all of these effects. Eventually, as he grows to adulthood, a particular "solution" to all the inner conflicts and vulnerabilities will solidify. He will be expansive and will display symptoms of narcissism, perfectionism, or vindictiveness. Or he will be self-effacing and compulsively compliant; he will display symptoms of neediness or codependence. Or he will be resigned and will display schizoid tendencies.
In Horney's view, mild anxiety disorders and full-blown personality disorders all fall under her basic scheme of neurosis as variations in the degree of severity and in the individual dynamics. The opposite of neurosis is a condition Horney calls self-realization, a state of being in which the person responds to the world with the full depth of his or her spontaneous feelings, rather than with anxiety-driven compulsion. Thus the person grows to actualize his or her inborn potentialities. Horney compares this process to an acorn that grows and becomes a tree: the acorn has had the potential for a tree inside it all along.
The term neurosis was coined by the 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. The meaning of the term was redefined by Carl Jung and Sigmund Freud over the early and middle 20th century. It has continued to be used in psychology and philosophy.
The Diagnostic and Statistical Manual of Mental Disorders (DSM) eliminated the category "neurosis" in 1980, because of a decision by its editors to provide descriptions of behavior rather than descriptions of hidden psychological mechanisms. This change has been controversial.
The term is derived from the Greek word (neuron, "nerve") and the suffix -? -osis (diseased or abnormal condition).