The aim of the study is to investigate vegetative reactivity at the different stages of major depressive disorder (MDD).

clinico-psychopathological method, clinico-anamnestic method, the Zung self-rating depression scale, the method of the heart rate variability analysis for assessment of vegetative regulation. The study is conducted from 2000 to 2007. In the first part of the study the assessment of vegetative regulation at the initial stage of MDD is provided (82 patients even 72 healthy persons). In the second part the vegetative regulation is studied at the stages of stabilization and reduction of MDD (76 patients even 66 healthy persons).

The results of investigation are shown reduction in the total heart rate variability, increase in tension level of regulatory systems at the initial stage of MDD. The activity balance of the sympathetic, parasympathetic and suprasegmental mechanisms of autonomic nervous system remains.

At the stage of depression stabilization the disruption of different components of autonomic nervous system balance occurs. The prevalence of the activity of suprasegmental ergotropic systems and the functional decrease of sympathetic mechanisms activity are observed. At the stage of the depression reduction the decrease of the activity of suprasegmental ergotropic systems with the hyper-activation of peripheral sympathoadrenal mechanisms are revealed.

Obtained data could be considered in chose and efficiency rating of therapy at the different stages of MDD.