A review of systems approaches to consultation-liaison psychiatry. The need for synthesis.

Five applications of systems theories to liaison psychiatry are reviewed. "Systems" is noted to have three distinct meanings as applied to consultation-liaison psychiatry: as a metatheoretical construct, as a decision-making process, and as an organizing construct for social variables. It is proposed that the time is ripe for synthesis of the social systems theories, reduction to the most parsimonious use of variables, and empirical testing of their importance. General systems theories are seen as needing further development before they will be routinely useful in consultation-liaison psychiatry.