Depression is the condition with the most robust psychedelic research evidence. Psilocybin therapy has shown results in randomized controlled trials that match or exceed the best antidepressants — often from just one or two sessions, with effects lasting months to years. Ketamine provides a faster-acting (hours rather than weeks) option that is already legally available nationwide.
Available treatments
The most studied option for major depression. Two sessions plus therapy produced 12-month remission in ~50% of participants in the Johns Hopkins trial. Legal in Oregon and Colorado; available in clinical trials nationally.
The only legally available option in all 50 states. IV ketamine infusions produce rapid antidepressant effects — often within hours. Spravato (esketamine) nasal spray is FDA-approved and covered by many insurance plans.
Primarily studied for PTSD, but depression that co-occurs with trauma may respond well to MDMA-AT. Phase 2 trials have shown benefits for treatment-resistant depression. Available through clinical trials.
Key research
Psilocybin-Assisted Therapy for Treatment-Resistant Depression
Johns Hopkins enrolled 24 adults with an average 17-year history of depression. After two psilocybin sessions: 71% showed >50% symptom reduction; 54% achieved remission. At 12 months, approximately half maintained remission. For a group that had failed multiple prior treatments, these numbers are unprecedented.
Psilocybin versus Escitalopram (SSRI) — Head-to-Head Trial
Imperial College London randomized 59 participants to 6 weeks of psilocybin therapy or escitalopram. Both showed similar depression score improvements — but psilocybin participants showed significantly greater improvements in emotional functioning, wellbeing, and the ability to feel pleasure. This was the first direct head-to-head comparison.
Is psychedelic therapy right for your depression?
The evidence is strongest for certain profiles — and weaker for others.
PTSD is notoriously difficult to treat. First-line medications help about half of patients; trauma-focused therapies like EMDR and CPT help more — but many people remain significantly impaired despite years of treatment. MDMA-assisted therapy appears to work through a fundamentally different mechanism: by temporarily reducing amygdala reactivity (fear response) while boosting oxytocin and empathy, it creates a window in which traumatic memories can be revisited and processed without re-traumatization.
Available treatments
The strongest evidence for PTSD. Three sessions over 18 weeks using the MAPS protocol. Currently available through clinical trials. Australia approved it in 2023 — US approval may follow pending new trial data.
Growing evidence for trauma-related depression and PTSD. Particularly promising for moral injury (guilt-based PTSD). Accessible through Oregon/Colorado licensed services and clinical trials.
Stanford's 2024 study of special operations veterans showed extraordinary PTSD outcomes. Available at licensed clinics in Mexico and other countries. Requires cardiac screening. Not for everyone.
Key research
MDMA-Assisted Therapy for Severe PTSD — Phase 3 Trial
The landmark MAPS Phase 3 trial enrolled 90 participants with chronic PTSD — many treatment-resistant for years. After three MDMA-AT sessions: 67% no longer met PTSD diagnostic criteria; 88% showed clinically significant improvement. The placebo group's remission rate was 32%. These results were maintained at 18-month follow-up in most participants.
Ibogaine Treatment for Special Operations Veterans
Stanford enrolled 30 special operations veterans, many with PTSD and traumatic brain injuries. One month after ibogaine treatment: 88% PTSD symptom reduction, 87% depression reduction, 81% anxiety reduction. Also showed improvement in TBI symptoms that are typically unresponsive to treatment. Currently only available internationally.
Is psychedelic therapy right for your PTSD?
Addiction is one of the most treatment-resistant conditions in medicine. Conventional approaches — medication-assisted treatment, 12-step, CBT — help many people but leave a large portion still struggling. Psychedelic therapy works differently: rather than managing cravings biochemically, it tends to address the underlying psychological drivers of addictive behavior — often producing shifts in self-concept, meaning, and motivation that patients describe as lasting changes in who they are, not just what they do.
Available treatments by substance
NYU's 2022 RCT showed 83% reduction in heavy drinking days. Hopkins trials show sustained abstinence. The mystical experience component strongly predicts outcome. Available through trials and OR/CO licensed services.
Hopkins pilot study showed 67% abstinence at 12 months — approximately 3x better than best available pharmacotherapy. Phase 3 trials are underway. Currently available through research enrollment.
Ibogaine appears to reset opioid receptor sensitivity, dramatically reducing or eliminating withdrawal. Available at licensed clinics in Mexico and other countries. Requires cardiac screening due to QT prolongation risk.
Key research
Psilocybin-Assisted Treatment for Alcohol Use Disorder
NYU's double-blind RCT enrolled 93 participants. At 8-month follow-up, psilocybin recipients showed 83% reduction in heavy drinking days vs. 51% in the active control. Of note: the mystical experience score during the session was the strongest single predictor of drinking outcomes — not the dose or the number of sessions.
Is psychedelic therapy right for your addiction?
Anxiety disorders represent some of the most common psychiatric conditions — affecting over 40 million Americans. Most respond to first-line treatments, but treatment-resistant generalized anxiety, social anxiety, and anxiety co-occurring with serious illness have far fewer effective options. Ketamine is the most accessible starting point; psilocybin is showing strong results particularly for anxiety with existential or grief dimensions; LSD is being studied for cluster headaches which involve significant anxiety components.
Immediately available. Rapid-onset anxiolytic effects alongside antidepressant action. Particularly useful when anxiety is severe or co-occurring with depression. Insurance may cover Spravato.
Strong evidence for cancer-related anxiety. Growing evidence for generalized anxiety. The shift in perspective on mortality and meaning that often emerges in psilocybin sessions is particularly relevant for existential anxiety.
Phase 2 evidence for social anxiety in autistic adults showed significant reductions. Anxiety that has roots in social trauma may respond particularly well to MDMA's empathogen effects.
Is psychedelic therapy right for your anxiety?
OCD is characterized by intrusive, unwanted thoughts (obsessions) and repetitive behaviors performed to relieve anxiety (compulsions). It affects about 2-3% of the population and is notoriously difficult to treat — even with first-line approaches like CBT with Exposure and Response Prevention (ERP) and SSRIs, a significant portion of patients remain significantly impaired. The theoretical rationale for psychedelic therapy in OCD is compelling: OCD is thought to involve excessive rigidity in certain brain circuits, and psychedelics' capacity to temporarily disrupt rigid default mode network patterns may offer relief.
Yale's 2006 open-label pilot (the first OCD-specific psilocybin study) showed 100% of participants improved — some dramatically. Phase 2 trials are now underway at multiple sites. The strongest theoretical fit of any psychedelic for OCD.
Case reports and small studies show rapid but often temporary OCD symptom reduction from ketamine infusions. May serve as a bridge treatment or as an adjunct to exposure therapy. Available now through ketamine clinics.
Important context for OCD
OCD research is at an earlier stage than depression or PTSD. The early results are extremely promising — but there are fewer trials, smaller samples, and less established protocols. If you're considering psychedelic therapy for OCD, clinical trial enrollment is the most appropriate path for now, as it offers the most rigorous protocols and safety monitoring. Ketamine therapy through a licensed clinic is a currently accessible option worth discussing with your psychiatrist.
The psychological distress associated with terminal illness — fear of death, loss of identity, meaninglessness, grief — is extraordinarily common and chronically undertreated. Antidepressants take weeks to work and often don't reach the existential dimensions of this distress. Psilocybin therapy appears to work precisely in this space: by producing experiences of unity, transcendence, and connection, it appears to fundamentally shift how people relate to their own mortality — not by removing the fear intellectually, but by providing a direct experience that reframes it.
The most compelling evidence base. Johns Hopkins and NYU have conducted multiple trials showing dramatic and lasting reductions in anxiety, depression, and demoralization from one to two sessions. FDA has granted breakthrough designation for this indication.
Ketamine infusions can rapidly reduce the depression and anxiety of serious illness. Available now through ketamine clinics. May provide relief while waiting for access to psilocybin therapy or clinical trials.
A note for family members and caregivers
If your loved one is facing a terminal diagnosis and conventional treatment has not adequately addressed their distress, psychedelic therapy is worth a serious conversation with their care team. The evidence for psilocybin in this context is some of the strongest in the field. Many participants and their families describe the experience as among the most meaningful of their lives — not just for the patient, but for those who supported them through it. Clinical trial enrollment is currently the most accessible path.