The core of psychology and the only thing that could legitimize it is the Diagnostic and Statistical Manual of Mental disorders or DSM. Mark R. Weaver made a point about this in closing arguments, claiming that the statistical data is the science behind the DSM https://www.youtube.com/watch?v=5tRQUKn2leo&t=256s and criticized John Mathew Fabian for not using the DSM and only going with his gut. https://www.youtube.com/watch?v=5tRQUKn2leo&t=282s handing out the diagnosis sonly on opinion. Now why would he do this? Was it because he was smart but sloppy https://www.youtube.com/watch?v=5tRQUKn2leo&t=247s That's one reason. Another is as pointed out above
Fabian admits that mental health professionals do not agree on the diagnostic standards of the DSM https://youtu.be/nmO2yi59qOU?t=1012 stating, that the agreement between professionals is not "extraordinary high"
What Fabian just admitted is that the DSM is the only thing that is suppose to legitimize psychology yet no one follows it. That psychologists tag people with diagnoses based on their own opinion literally vs a standardized diagnostic criteria which is varies as much as say someone likes a certain color. Fabian states psychologists only use the DSM as a "guide"
Now why is that. First it should be pointed that the DSM has hard editions,
DSM-1 (1952) DSM-II (1968) DSM-III (1980) DSM-III-R (1987) DSM-IV (1994) DSM-IV-TR (2000) and DSM V in 2013. These are radical changes where diagnoses have been added and removed, yes removed. two glaring examples have been Asperger's Syndrome and ADD as stand alone diagnoses. Asperger's was first coined in 1944 but was removed from the DSM in revision 5 in 2013. https://pubmed.ncbi.nlm.nih.gov/28953765/#:~:text=Abstract,5%20diagnosis%3A%20Autism%20Spectrum%20Disorder. People previously Asperger's are now diagnosed as being on the autistic spectrum which many feel is a more stigmatizing diagnosis. going from a fine tuned to a broad stroke. Another of these broader strokes is removing Attention Deficit Disorder as a stand alone diagnosis that did not incorporate a hyperactive component, This was removed in the DSM-IIIR and DSM-4 between 1987 and 1994 https://www.thehealthyjournal.com/faq/why-is-add-not-a-diagnosis-anymore
REPLICATION CRISIS, STATISTICS CANNOT BE DUPLICATED DUE TO NORMS CHANGE
https://www.cchr.org/documentaries/diagnostic-and-statistical-manual/watch.html
https://www.psychologytoday.com/us/blog/rethinking-mental-health/201207/the-great-dsm-hoax
https://lareviewofbooks.org/article/scientific-nightmare-the-backstory-of-the-dsm/
https://abcnews.go.com/Health/MindMoodNews/dsm-fire-financial-conflicts/story?id=15909673
https://www.freedommag.org/english/vol29i2/page04a.htm