Other Medicines

Psilocybin is the most studied classical psychedelic in the current therapeutic renaissance, but it exists within a broader pharmacological landscape that includes MDMA, ketamine, LSD, DMT, mescaline, and ibogaine — each with distinct mechanisms, risk profiles, durations, and therapeutic indications. Understanding the landscape matters for practitioners, researchers, and anyone seeking to make sense of the rapidly evolving clinical evidence.

MDMA (3,4-methylenedioxymethamphetamine) acts primarily through massive serotonin, dopamine, and norepinephrine release rather than direct 5-HT2A agonism. Its unique capacity to produce feelings of trust, interpersonal openness, and reduced fear response while maintaining full lucidity makes it particularly well-suited for processing trauma in a therapeutic relationship. MAPS's Phase 3 trials for PTSD showed 67% of participants no longer meeting PTSD diagnostic criteria after three sessions — the most dramatic efficacy signal in psychiatric drug development in decades.

Ketamine occupies a distinct pharmacological niche as an NMDA receptor antagonist rather than a serotonergic compound. Its rapid antidepressant effects (within hours rather than weeks) and FDA-approved nasal spray formulation (esketamine/Spravato) make it currently the most accessible psychedelic-adjacent treatment. Ketamine's mechanisms differ significantly from psilocybin's, but both produce BDNF upregulation and synaptic plasticity through downstream pathways.

OOTW Journal maintains intellectual rigor about these distinctions. Lumping all psychedelics together because they're federally scheduled obscures meaningful pharmacological differences. Our articles in this collection provide mechanistic grounding for understanding how these substances differ — and what those differences mean for therapeutic application.