The mechanisms of psychedelic therapy

‘The mechanisms of psychedelic therapy’ presents arguments against three theories of psychedelic therapy. The Molecular Neuroplasticity Theory ascribes therapeutic benefits to an experience-independent molecular mechanism. This theory is undermined by the correlation between ‘mystical-type experiences’ and beneficial outcomes, which suggests that genuinely psychological mechanisms are involved. The Metaphysical Belief Theory and the Metaphysical Alief Theory fare better on this count: both ascribe beneficial outcomes to the transcendent vision of a ‘Joyous Cosmology’ supposedly encountered in the mystical-type experience. However, these theories struggle to account for the fact that some patients satisfy psychometric criteria for a mystical-type experience without undergoing a non-naturalistic metaphysical hallucination. The psychometric criteria can also be satisfied by more naturalistic experiences of ego dissolution and connectedness. The conclusion is that psychedelics cause lasting benefits via some genuinely psychological factor that (i) correlates with the construct of a mystical-type experience, but (ii) is independent of non-naturalistic metaphysical ideations.