I have tried to show that psychiatric research can be empirical and experimental, controlled, and operational and not dependent on inferences, analogies, or anecdotes. Hypotheses can be derived which are testable. Theory is a different matter. At the present we rely heavily on psychoanalytic theory or on still poorly formulated and defined general systems theory, information theory, or transactional theory. To explain the depth and variety of the interrelationship of somatopsychosocial facets of the totality of human behavior in process requires a unified theory of human behavior which we have not yet even approached. Integration or synthesis of biological, psychological, and social theory is not enough.

Ginker (1964) as cited in: S. Nassir Ghaemi (2009) The Rise and Fall of the Biopsychosocial Model. p. 24