Schizoaffective disorder: the past and the future of hybrid construction

Abstract
The article argues for the discrepancy between the artificial construction of «schizoaffective disorder» (SAD) and the principles of nosological diagnostics. The term of «acute schizoaffective psychoses», was introduced by Y. Kazanin in 1933, is still remain a controversial nosological unit. This diagnosis often made at the cut of a psychotic episode on a «dichotomous scale» by «weighing» schizophrenic and affective symptoms. In the history of the creation of the concept of SAD, there is a tendency towards reductionism and the search for universal manifestations. Each individual clinical case must be considered holistically. It is unacceptable to extract the individual signs (which does not fit syndromal structures) from general picture of the disease. However, this requirement is in contradiction with the current trends towards simplification, discreteness and loss of clinical thinking in currents classifications of diseases. The inadequacy of the available diagnostic approaches and criteria for distinguishing between SAD, bipolar disorder and schizophrenia leads to the fact that the patient’s diagnosis is based on the subjective preferences of a clinician, and during patient’s life can many times be changed. The results of the the phenotype and genotype of the corresponding disorders searching partially shed light on the features of the diagnosis; but at the same time, some researchers are artificially combine the discrete properties and coming to incorrect conclusions; often such an identity simply does not make sense. The authors join opinion of experts who suggesting the existence of a «third psychosis» or even several discrete forms of diseases, which, along with unrecognized attacks of bipolar psychosis and schizophrenia are still mistakenly dissolved in the dichotomous / dimensional hybrid SAD. Diagnostics, taking into account the follow-up, regularities of the course, pathophysiological changes and psychopathological structure, has not only clinical value, but is also responsible for the selection of effective treatment, correct preventive measures, affects the social status and, ultimately, the quality of life of the patient.