Let me be clear in that I am not necessarily disagreeing with you. I manage the medical problems of many psych patients and treat depression, anxiety, etc. to a certain degree. My point is that psych, in many regards, is border-line pseudo science. You call it a discipline "in its infancy." So be it. But, my "complaints" about psych are the same voiced by many MD/DO psychiatrists. If I owned the world, there would be no psychiatrists, only neuro-psych. The APA has sold their souls to self-preservation, while kicking real science and evidence to the curb. The DSM-5, the supposed penultimate result of decades of psychiatric research, is exhibit A in not just pseudoscience, but pseudoscience at its worst.
Again, this isn't just some dumb, uneducated, political-axe-grinding FNP saying this, psychiatrists are saying this. Psychiatry at this point is nothing more than "academic" psychology combined with a medical degree, i.e. social scientists with a prescription pad. There is seemingly less interest in basic biology of the brain, neuronal molecular mechanisms and how they related to behavior, etc. and more interest in political agendas. A 16 year old female that thinks she is a cat trapped in a human body is a "normal variation of human behavior." As is the early 20's female who thinks she is a vampire, that is "due to an underlying anemia that medicine does not yet have the ability to fully appreciate." Meanwhile, a 7 year old boy who talks too much in class needs intensive meth therapy STAT! Not to call out an entire profession, of course, as there are many in the profession who agree with what I am saying.
In regard to the discussion at hand, I think Zen is an awesome dude with weird ideas. Let me emphasize awesome dude. Who seems super cool! And he probably has as much "evidence" to back him up as every other therapist/psychiatrist/faith healer/counselor/motivational speaker/whatever person does.