The monograph for the first time presents the theory of a systemic approach in psychology; developed the foundations of the theory of system analysis; the theoretical model of the psyche as a system is justified; a systemic research technology is proposed with the identification of "units" of mental analysis based on the characteristics of the "brain - psyche "relationship. The systemic solution of the psychological problem leads to the unification of the branches of psychological knowledge and forms a new direction of research - systemic psychology.