There seem to be significant questions that need to be answered by experts after an examination of the changes to the definition of "schizophrenia" in DSM-5, while working within the model of MPAPT.

For example (quoting from the article):

Two changes were made to the primary symptom criteria for schizophrenia.

According to the APA, “the first change is the elimination of the special attribution of bizarre delusions and Schneiderian first-rank auditory hallucinations (e.g., two or more voices conversing). In DSM-IV, only one such symptom was needed to meet the diagnostic requirement for Criterion A, instead of two of the other listed symptoms. This special attribution was removed due to the nonspecificity of Schneiderian symptoms and the poor reliability in distinguishing bizarre from nonbizarre delusions.

“Therefore, in DSM-5, two Criterion A symptoms are required for any diagnosis of schizophrenia.”

The second change was the requirement for a person to now have at least one of three “positive” symptoms of schizophrenia:

Hallucinations
Delusions
Disorganized speech

The APA believes this helps increase the reliability of a schizophrenia diagnosis.

Thus, because the American Psychiatric Association (APA) has made changes to the definition of "schizophrenia," it would seem that all research on "schizophrenia" conducted to this point is no longer valid, because how can you change the definition of a thing and say the old research using the old definition still applies under the new definition? And what do you do about research currently in progress?

And does it not also logically follow that all those currently labeled under the old criteria must be re-evaluated.

And this must go for all research and "diagnoses" surrounding "disorders" for which changes were made.

2013; edited for clarity, 2017.