Psychiatric diagnoses and systems of disease classification are tools
which serve many purposes in the clinical routine, in research, and in
health administration. Good quality research in psychopharmacology is
based upon reliable diagnostic concepts, but at the same time results
produced by this research also serve as an important source for valid
ation of diagnostic concepts. The dialectic interaction between descri
ptive concepts of illness on the one hand and the results of experimen
tal research on the other illustrates the need for continual developme
nt of up-to-date diagnostic terminology and revised classification sys
tems. The coming of ICD-11 is imminent.