Perhaps an apt corollary to this question is: Is classification of psychotic disorders like schizophrenia going to improve treatment results? Which offers the best hope for improvement for these patients: better diagnostic techniques and technology or basic research into the nature and course of this disorder?
The reliability of the DSM-5 diagnosis of schizophrenia is dealt with in the second paragraph of an editorial in the American Journal of Psychiatry. The conclusion is that DSM-5 is an improvement.http://ajp.psychiatryonline.org/article.aspx?articleid=1555604