Are the Subjective Effects of Psychedelics Necessary for Their Therapeutic Benefits?

Participants in psychedelic studies frequently report that the mystical experiences they have while under the influence of psychedelics are among the most meaningful experiences of their lives. Further, scores on the Mystical Experience Questionnaire taken immediately after the session have been found to predict positive outcomes several months later.

Nevertheless, could it be that mystical experiences are merely the phenomenological correlate of the brain entering a high energy state, and that it is an increase in neuroplasticity that truly drives the effect? See this article from the Psychedelic Review for arguments on both sides and an experimental paradigm that might shed further light on these questions.