Neurosis, according to Sigmund Freud, arose from inner conflicts and could lead to anxiety. In his formulation, the causal factors could be found roughly in the first six years of life, when the personality, or ego, is weak and afraid of censure. He attributed neurosis to the frustration of infantile sexual drives, as when severe eating and toilet habits and other restrictions are parentally imposed, which appear in adulthood as neurotic symptoms .
Other authorities have emphasized constitutional and organic factors. Among the psychoanalysts, Alfred Adler and H. S. Sullivan stressed social determinants of personal adjustment, and Karen Horney emphasized insecurity in childhood as causes of neurosis.
Until 1980, neuroses included anxiety disorders as well as a number of other mild mental illnesses, such as hysteria and hypochondria. Anxiety disorders are fairly common, and generally involve a feeling of apprehension with no obvious, immediate cause. Such intense fears of various situations may be severe enough to prevent individuals from conducting routine activities. Phobias, the most common type of anxiety disorder, involve specific situations which cause irrational anxiety attacks.
For instance, an individual with agoraphobia (fear of open spaces) may be too anxious to leave their house. Obsessive-compulsive disorder occurs when an individual relentlessly pursues a thought or action in order to relieve anxiety.
Panic disorder is characterized by anxiety in the form of panic attacks, while generalized anxiety disorder occurs when an individual experiences chronic anxiety with no apparent explanations for the anxiety. Post-traumatic stress disorder, occurring in the wake of a particularly traumatic event, can lead to severe flashbacks and a lack of responsiveness to stimuli. Anxiety disorders are usually accompanied by a variety of defense mechanisms, which are employed in an attempt to overcome anxiety. Hypochondriasis and hysteria (now generally known as conversion disorder) are classified today as somatoform disorders, and involve physical symptoms of psychological distress.
The hypochondriac fears that minor bodily disturbances indicate serious, often terminal, disease, while the individual suffering from conversion disorder experiences a bodily disturbance-such as paralysis of a limb, blindness, or deafness-with no clear biological origin. Treatment of neurosis may include behavior therapy to condition an individual to change neurotic habits, psychotherapy, and group psychotherapy. Various drugs may also be employed to alleviate symptoms.