Neurosis
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 (DSM) in 1980 with the publication of DSM III. However, 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. Nor should it be mistaken for neuroticism, a fundamental personality trait proposed in the Big Five personality traits theory.

Etymology
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.  The meaning of the term was redefined by Carl Jung and Sigmund Freud over the early and middle 20th century, and has continued to be used in psychology and philosophy.The Diagnostic and Statistical Manual of Mental Disorders (DSM) eliminated the neurosis category 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. Likewise, according to the American Heritage Medical Dictionary, neurosis is "no longer used in psychiatric diagnosis."

Symptoms and causes
Neurosis may be defined simply as a "poor ability to adapt to ones environment, an inability to change ones life patterns, and the inability to develop a richer, more complex, more satisfying personality." There are many different neuroses, including:

obsessive–compulsive disorder
obsessive–compulsive personality disorder
impulse control disorder
anxiety disorder
histrionic personality disorder
dissociative disorder
a great variety of phobiasAccording to C. George Boeree, professor emeritus at Shippensburg University, the symptoms of neurosis may involve:
... 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.

Jungian theory
Carl Jung found his approach particularly effective for patients who are well adjusted by social standards but are troubled by existential questions. Jung claims to have "frequently seen people become neurotic when they content themselves with inadequate or wrong answers to the questions of life".: 140  Accordingly, the majority of his patients "consisted not of believers but of those who had lost their faith".: 140  A contemporary person, according to Jung, …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.: 82 Jung found that the unconscious finds expression primarily through an individuals 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 his Psychological Types. Jung also found collective neuroses in politics: "Our world is, so to speak, dissociated like a neurotic.": 85

Psychoanalytic theory
According to psychoanalytic theory, neuroses may be rooted in ego defense mechanisms, though 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). However, only those thoughts and behaviors that produce difficulties in ones life should be called neuroses.
A neurotic person experiences emotional distress and unconscious conflict, which are manifested in various physical or mental illnesses; the definitive symptom being anxiety. Neurotic tendencies are common and may manifest themselves as acute or chronic anxiety, depression, an obsessive–compulsive disorder, a phobia, or a personality disorder.

Horneys theory
In her final book, Neurosis and Human Growth, Karen Horney lays 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 proposes that neurosis is transmitted to a child from their early environment and that there are many ways in which this can occur:: 18 
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 childs initial reality is then distorted by their parents needs and pretenses. Growing up with neurotic caretakers, the child quickly becomes insecure and develops basic anxiety. To deal with this anxiety, the childs imagination creates an idealized self-image:: 22 
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 they identify themselves with their idealized image, a number of effects follow. They will make claims on others and on life based on the prestige they feel entitled to because of their idealized self-image. They will impose a rigorous set of standards upon themselves in order to try to measure up to that image. They will cultivate pride, and with that will come the vulnerabilities associated with pride that lacks any foundation. Finally, they will despise themselves for all their limitations. Vicious circles will operate to strengthen all of these effects.
Eventually, as they grow to adulthood, a particular "solution" to all the inner conflicts and vulnerabilities will solidify. They will be either 

expansive, displaying symptoms of narcissism, perfectionism, or vindictiveness
self-effacing and compulsively compliant, displaying symptoms of neediness or codependence
resigned, displaying schizoid tendenciesIn Horneys 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 their spontaneous feelings, rather than with anxiety-driven compulsion. Thus the person grows to actualize their 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.

See also
Individuation
Neurotics Anonymous
Positive disintegration

References
Bibliography
Angyal, Andras. 1965. Neurosis and Treatment: A Holistic Theory, edited by E. Hanfmann and R. M. Jones.
Fenichel, Otto. 1945. The Psychoanalytic Theory of Neurosis. New York: Norton.
Freud, Sigmund. 1953–1974. The Standard Edition of the Complete Psychological Works of Sigmund Freud. (24 vols.), translated by J. Strachey. London: Hogarth.
Horney, Karen. 1937. The Collected Works. (2 vols.). Norton.
—— 1945. Our Inner Conflicts. Norton.
1950. Neurosis and Human Growth. Norton.
Horwitz, A. V. and J. C. Wakefield. 2007. The Loss of Sadness: How Psychiatry Transformed Normal Sorrow into Depressive Disorder. Oxford University Press. ISBN 978-0-19-531304-8.
Jung, Carl G. [1921] 1971. Psychological Types, (The Collected Works of C. G. Jung 6). Princeton University Press. ISBN 0-691-01813-8.
—— 1966. Two Essays on Analytical Psychology, (The Collected Works of C. G. Jung 7). Princeton University Press. ISBN 0-691-01782-4.
Jung, Carl G., and Aniela Jaffé. [1961] 1989. Memories, Dreams, Reflections. New York: Vantage Books. ISBN 0-679-72395-1
Jung, Carl G., et al. 1964. Man and His Symbols. New York: Anchor Books / Doubleday. ISBN 0-385-05221-9.
Ladell, R. M., and T. H. Hargreaves. 1947. "The Extent of Neurosis." British Medical Journal 2(4526):548–49. doi:10.1136/bmj.2.4526.548. PMC 2055884. PMID 20267012.
López-Piñero J.M. (1983) Historical Origins of the Concept of Neurosis (Translated by D. Berrios) Cambridge, Cambridge University Press
McWilliams, Nancy. 2011. Psychoanalytic Diagnosis: Understanding Personality Structure in the Clinical Process (2nd ed.). Guilford Press. ISBN 978-1-60918-494-0.
Russon, John. 2003. Human Experience: Philosophy, Neurosis, and the Elements of Everyday Life. Albany: State University of New York Press. ISBN 0-7914-5754-0
Winokur, Jon. 2005. Encyclopedia Neurotica. ISBN 0-312-32501-0.

External links

Janov, Arthur (1991). "Neurosis". Retrieved 2009-04-21.