[Mechanisms of the development of recurrences of endogenous psychoses. The duration of remission in schizophrenia]. / O mekhanizmakh razvitiia retsidivov pri éndogennykh psikhozakh. Dlitel'nost' remissii pri shizofrenii.

The distribution of the period of schizophrenia remissions is depicted by the exponential law. Having carried out an expensive epidemiological study, the authors have shown that such a depiction may turn adequate only in the design of the distribution in time intervals of the order of one year. In minor time intervals (weekly or approximating ones), the distribution acquires a wavy appearance indicating periodic fluctuations of relapse risk at the basis of which there lies a certain rhythmical process. The data are provided in favour of polyrhythmic pattern of that process, with the rhythms having a period of 5-6, 8-9, 12-13 and 21-22 weeks being the most permanent ones. The correlation between the exponential and polyrhythmic models of schizophrenia relapsing is discussed.