Depression or dysphoria in its various forms is probably the commonest single symptom encountered in military psychiatry, and its differential diagnosis is often a matter of extreme difficulty: The author's observations, based on three years' experience as psychiatrist in a military psychiatric hospital, have shown that of a large number of cases admitted with a diagnosis of “depressive psychosis,” by far the greater proportion are not psychotic at all, but are cases of an acute reactive neurotic disturbance, characterized by a variety of mixed anxiety, hysterical and psychopathic features, and combined with a marked disturbance in the sphere of affect and personality.