This is a severe disorder of thought/cognition, experience, and behavior.
It consists of a severe disorder of...

auch: experiential disorder
... thought/cognitive, experiential and behavioral disorder

cognition comprises more than just thinking,
cognition includes perception (Wahrnehmung), memory (Gedächtnis), Problemlösen,...

So, according to Claus, I would just write

disorder of thought, experience and behavior (British: behaviour)