[The substance of the concept of "phobia"].

As a result of clinico-psychopathological analysis of the structure and mechanisms of development of obsessive phobias and related events, the 3 groups of these are singled out: (1), phobias as the states caused by paroxysmal fear appearing in distinct situations; (2), pseudophobias--the anxious states; (3), phobia-like states caused by various events. Phobias, themselves, are subdivided into 4 species according to the genesis of relevant fear. The differences between these forms are described with the differential diagnostic issues pointed out.