Psilocybin vs. MDMA for PTSD — different mechanisms, different tools?

The mechanistic difference is meaningful: MDMA primarily allows trauma processing by reducing the fear response while maintaining lucid memory access. Patients can recall and process specific traumatic memories in a state of reduced threat. Psilocybin produces more profound ego dissolution and doesn't typically allow lucid memory work in the same way. The mechanism is different enough that the clinical indication may not be fully overlapping.

There's a practical argument for psilocybin's particular relevance for moral injury (versus fear-based PTSD where MDMA's mechanism is particularly apt). Moral injury involves shame, guilt, and value destruction — not the threat-response fear circuit that MDMA addresses most directly. Psilocybin's capacity for self-compassion, meaning-making, and spiritual experience may address the moral injury dimension more effectively.

The honest answer is we don't know yet. No trial has compared them head-to-head in the same PTSD population. Clinical hypothesis would be: MDMA for classic trauma/fear-based PTSD, psilocybin for complex PTSD with identity disruption and moral injury. But this is speculation — the trial data to test it doesn't exist.