CODE is an acronym for Composite Diagnostic Evaluation. It is a poly-diagnostic method comprised of a set of symptoms (codes”) which can provide diagnoses in all its component diagnostic systems; a semi-structured interview for the elicitation of all the symptoms in terms of present or absent; and diagnostic decision trees which, by specially devised algorithms organize the symptoms into distinct psychiatric disorders in the component diagnostic systems. The term was introduced in 1989 by Thomas A. Ban in his book, CODE-DD Composite Diagnostic Evaluation of Depressive Disorders. The methodology was developed for uncovering idiosyncratic diagnoses affected by psychotropic drugs in clinical trials in which patients are included on the basis of their “consensus-based diagnoses” (Ban 1989, 1991).


Ban TA. CODE-DD Composite Diagnostic Evaluation of Depressive Disorders. Brentwood: JM Productions, Inc; 1989.

Ban TA. CODE System: Theory and practice. In: Aguglia E, Ban TA, editors. International Symposium on Functional Psychoses Today. Rome: John Libbey; 1991, pp. 279-95.


Thomas A. Ban

June 11, 2015