The psychoneurosis group includes those disorders in which mental forces or ideas of which the subject is either aware (conscious) or unaware (subconscious) bring about various mental and physical symptoms - in other words these disorders are essentially psychogenic in nature.

The term "neurosis" is now generally used synonymously with psychoneurosis, although it has been applied to certain disorders in which, while the symptoms are both mental and physical, the primary cause is thought to be essentially physical. In most instances, however, both psychogenic and physical causes are operative and we can assign only a relative weight to the one or the other.

The following types are sufficiently well defined clinically to be specified:

(a) Hysterical type: Episodic mental attacks in the form of delirium, stupor or dream states during which repressed wishes, mental conflicts or emotional experiences detached from ordinary consciousness break through and temporarily dominate the mind. The attack is followed by partial or complete amnesia. Various physical disturbances (sensory and motor) occur in hysteria, and these represent a conversion of the affect of the repressed disturbing complexes into bodily symptoms or, according to another formulation, there is a dissociation of consciousness regarding some physical function.

(b) Psychasthenic type: This includes also the compulsive and obsessional neuroses of some writers. The main clinical characteristics are phobias, obsessions, morbid doubts and impulsions, feelings of insufficiency, nervous tension and anxiety. Episodes of marked depression and agitation may occur. There is no disturbance of consciousness or amnesia as in hysteria.

(c) Neurasthenic type: This should designate the fatigue neuroses in which physical as well as mental causes evidently figure; characterized essentially by mental and motor fatigability and irritability; also various hyperesthesias, paresthesias, hypochondriasis and varying degrees of depression.

(d) Anxiety neuroses: A clinical type in which morbid anxiety or fear is the most prominent feature. A general nervous irritability (or excitability) is regularly associated with the anxious expectation or dread; in addition there are numerous physical symptoms which may be regarded as the bodily accompaniments of fear, particularly cardiac and vasomotor disturbances: the heart's action is increased, often there is irregularity and palpitation; there may be sweating, nausea, vomiting, diarrhoea, suffocative feelings, dizziness, trembling, shaking, difficulty in locomotion, etc. Fluctuations occur in the intensity of the symptoms, the acute exacerbations constituting the "anxiety attack."