Implications of the distinction between organic and functional psychoses.

On the basis of their symptomatology, some psychoses are called organic. The remaining psychoses are called functional. It is generally supposed that symptomatically organic psychoses have organic causes and thus call for medical investigations, while the functional psychoses are not so caused, and call for a dynamic formulation rather than an organic one. The author examines the basis for this distinction, and argues that it is logically unsound. He gives examples of exceptions to the rule, both organic-seeming illnesses that are the consequence of psychological mechanisms, and symptomatologically functional psychoses with organic antecedents. The exceptions prove to be so numerous that a different approach to the investigation of the psychoses, an approach stressing antecedents rather than symptomatology, appears to be called for.