This condition is characterized by complaints of chronic weakness, easy fatigability, and sometimes exhaustion. Unlike hysterical neurosis the patient's complaints are genuinely distressing to him and there is no evidence of secondary gain. It differs from Anxiety neurosis and from the Psychophysiologic disorders in the nature of the predominant complaint. It differs from Depressive neurosis in the moderateness of the depression and in the chronicity of its course.
As of DSM-III, this disorder is no longer part of the DSM.