Models of exogenous and endogenous sleep perturbation as diagnostic and therapeutic predictors in depression

In a group of 60 samples divided into three subgroups: a) healthy, b) exogenic (non-psychotic) and c) endogenic (psychotic) depressives, nocturnal sleep (10 p.m. to 6 a.m.) was registered according to accepted standards. 130 parameters (variables) of hypnograms were exposed to exact statistical testing. Mathematical modes were formed through satisfactory conditions of N-distribution by the method of discriminative analysis ("step by step"). These models were called "The Discriminative Profile of Sleep" (DPS). The Model of Exogenic Perturbation of Sleep is characteristic of exogenic (reactive) depressive disturbances. The dominant discriminative factors of this model are: increased number of nocturnal awakenings (NAW) and fragmentation of nocturnal sleep. The Model of Endogenic Perturbation of Sleep is formed by: shortened REM-latency, reduction of delta-sleep, increase of the Index of Endogenic Periodicity/Perturbation (IEP). These models contribute not only to the problem of correct differential diagnosis, but also to the accurate choice of therapy, the appraisal of therapeutic sensitivity-insensitivity following the course of illness, and a more precise final result. According to these models, depression in relation to the structure of nocturnal sleep is defined as: hypnofragmentic exogenic (reactive) depression, and hypnodisrrhythmic endogenic depression (or where endogenic perturbation developed during the illness).