The necessity of developing a two-stage qualification in ICD-11.

In the International Classification of Diseases, 10th Revision (ICD-10) two opposing principles are combined and mixed: atheoreticity that is necessary for the natural classification and commitment to nosology. Implementation of these principles requires a two-stage qualification. The first stage should be narrative detailed syndromological qualifications with identification of psychotic level of disorders. As for the second stage, the qualification should be nosological, based on complete clinical analysis, which is far from being possible to realize at once. ICD-10, specifically brought to nosological certainty, may remain the natural foundation for nosological qualification. Implementation of the syndromic qualification at the first stage will allow to consider nosological features of each syndrome at the second stage and to expand the list of criteria in different clusters. Such a suggestion opens the prospect for subsequent revisions of the ICD and allows to direct our efforts and those of practitioners to the unified channel, where the statistical goals would not be implemented at the expense of the research ones.