The Classification is arbitrary and essentially clinical. Diagnosis can be difficult and it may take time to be certain of distinguishing between Schizophrenia and Drug intoxication.

A major distinction , based upon the gravity of symptoms and the patient’s grasp upon reality is between the Neuroses and the Psychoses.

The Neurotic patient is aware of himself and his surroundings and is orientated in time and place. He has some insight into his condition.

The Psychotic patient is prey to delusions and hallucinations. He hears voices inside his head, he sees visions, he is deeply disturbed by the threatening world he sees and hears all about him where the most innocent action is construed as a personal attack.

A severely depressed person may become Psychotic although the affective disorders are more often neuroses.