In the paper possible neurophysiological mechanisms are described which are the basis of formation of inadequately coloured negative emotions and of disturbance of cognitive function in patients with depressive syndrome within maniac-depressive psychosis and schizophrenia. Analysis of interconnection between posterior brain regions where sensory information comes in, and anterior regions where evaluation of the incoming information takes place, has shown that in the moment of emotions formation and fulfillment of the task of reaction choice from three alternatives between these parts "transversal functional block" is revealed mainly in the left hemisphere what is manifested in phase shifts of the evoked potential waves. This block may be the basis of disturbance of normal exchange of impulse activity between them and in its turn prevent formation of adequately coloured emotions and realization of normal cognitive function. On the basis of the present study a method is proposed which includes medical electric stimulation, in response to which a quick response activity of the patient is required, based on reaction choice from three alternatives. This method promotes weakening of the functional block and improvement of clinic state of patients with depressive syndrome.