Because dysfunctional thought when alone cannot be challenged, and becomes self reinforcing. A therapist helps a patient examine the ways in which their thinking is detrimental to their wellbeing.

Theoretically, maybe. But they could just as likely, or maybe more likely, just make it worse. They definitely made it worse it ny case. It was a very reckless process, from my perspective.

"Thought" is a very broad term. You cannot "swear off" a broken leg. That doesn't negate the existence of the placebo effect, or people who do ridiculous things like walk a mile for help without realizing it's broken.

And with psychology just remember Freud. Not that things haven't gotten better, but I still consider that there could be real possibility of either miss- or overdiagnosis...

Aspergers/ASD is a neurological condition, not just psychological