Much current thinking holds psychiatric diagnosis to be "the soft underbelly of psychiatry"4 and "an indictment of the present state of psychiatry."7 Diagnosis is said to cause behavioral scientists "marked feelings of inferiority"6 because of their alleged inability to obtain agreement rates significantly better than chance.5 To the extent that these opinions are accurate, it is clearly an important question why a nomenclature, which is the distillation of so much experience over so many years,1 should so fail the test of clinical usefulness. It is equally clear that the problems involved are complex and vexing, not likely amenable to any quick or easy solution.
A previous paper2 reviewed the literature on concurrence of diagnoses and pointed out that prior studies had methodological limitations which may have spuriously lowered diagnostic agreement. In another article,3 we reported the results of a