Weekly Psychedelic News – Week 29, 2023

Stay up-to-date with the latest in the world of psychedelics with our weekly news roundup for week 29 of 2023. Read about the latest research, policy updates, and industry developments in the rapidly growing field of psychedelic science.

Positive Data From COMPASS Pathways’ Phase 2 Trial Combining Psilocybin & SSRIs

COMPASS Pathways plc (Nasdaq: CMPS), a biotechnology company focused on mental health, has announced positive data from an open-label phase 2 clinical trial of COMP360 psilocybin in combination with selective serotonin reuptake inhibitors (SSRIs) for treatment-resistant depression in the peer reviewed Nature journal, Neuropsychopharmacology. The trial involved 19 participants, and the results showed that SSRIs did not interfere with the potential therapeutic effect of COMP360.

  • Response (a greater than 50% reduction from baseline in MADRS total score[1]) and remission (MADRS total score of 10 or less) was seen in 42% of participants at week three.
  • The efficacy findings were similar to those from COMPASS’s Phase 2b study of 25mg of COMP360 psilocybin in treatment-resistant depression, where patients were withdrawn from their antidepressants prior to receiving COMP360 (42% response and remission rates at week three versus 37% and 29%, respectively).
  • COMP360 psilocybin treatment was generally well tolerated. The most common treatment emergent adverse event was headache. No serious adverse events were reported.

Dr. Guy Goodwin, Chief Medical Officer at COMPASS Pathways, said, “It has long been thought that SSRIs could interfere with the potential therapeutic effect of psilocybin. This data is exciting because it provides a preliminary signal that this is not the case, and that patients could remain on their SSRI antidepressant medication and experience the same effect from COMP360 psilocybin treatment as people who are not on SSRIs. This could have important clinical implications for patient choice, if COMP360 psilocybin treatment receives regulatory approval for treatment-resistant depression. Withdrawing from antidepressants can be unwelcome for some patients, so the possibility of having the choice to remain on their antidepressant could eventually make COMP360 psilocybin treatment more accessible.”

New Study Reveals Ketamin’s Effectiveness Against Treatment-Resistant Depression

The phase 3 trial on generic ketamine for treatment-resistant depression (TRD) has shown promising outcomes. The double-blind, randomized, multicenter trial conducted in Australia and New Zealand found that adequately dosed subcutaneous racemic ketamine proved effective and safe in treating TRD over a 4-week treatment period. The results, published in The British Journal of Psychiatry and in the Cambridge University Press, demonstrated a significant difference in remission rates between patients receiving higher-dose ketamine (19.6%) and those in the control group receiving midazolam (2.0%). These findings highlight the potential of generic ketamine as a viable option for treating patients with treatment-resistant depression.


In this phase 3 trial conducted at seven mood disorders centers in Australia and New Zealand, participants with treatment-resistant depression were given twice-weekly subcutaneous racemic ketamine or midazolam for 4 weeks. The trial initially compared fixed-dose ketamine (0.5 mg/kg) with midazolam (0.025 mg/kg) in cohort 1. However, dosing was later revised based on a recommendation from the Data Safety Monitoring Board to flexible-dose ketamine (0.5–0.9 mg/kg) or midazolam (0.025–0.045 mg/kg) with response-guided dosing increments in cohort 2. The primary outcome measured was remission, defined as a Montgomery-Åsberg Rating Scale for Depression score of 10 or lower, at the end of week 4.


In the final analysis of the phase 3 trial, involving 68 participants in cohort 1 (fixed-dose) and 106 participants in cohort 2 (flexible-dose), ketamine demonstrated higher efficacy compared to midazolam in cohort 2, with a remission rate of 19.6% versus 2.0%. However, there was no significant difference in efficacy between ketamine and midazolam in cohort 1. Ketamine was well-tolerated, and any acute adverse effects, such as psychotomimetic effects and blood pressure increases, were resolved within 2 hours. These findings indicate that ketamine shows promise as an effective and safe treatment option for patients with treatment-resistant depression.


Adequately dosed subcutaneous racemic ketamine was efficacious and safe in treating TRD over a 4-week treatment period. The subcutaneous route is practical and feasible.

Texas Doctors will explore psychedelic-assisted psychotherapy for gynecologic cancer patients

In their published paper, a group of Texas doctors explored the potential benefits of psilocybin-assisted psychotherapy in alleviating uncertainty and overwhelming grief experienced by women undergoing treatment for gynecologic cancer, particularly in the late stages of the disease. The researchers analyzed data from 10 clinical trials, revealing that just one or two doses of psilocybin can lead to rapid and enduring antidepressant effects lasting up to 6 months. These findings suggest that psilocybin therapy could offer promising support for women facing the emotional challenges of gynecologic cancer treatment.

In conclusion, while cognitive-behavioral therapy may be effective in addressing the distress of cancer patients, its demands on commitment and stamina can be challenging for patients already facing physical and emotional struggles. Psychedelics offer a potential alternative route to relief, allowing patients to work through their negative emotions more quickly. This is especially crucial for the emerging cohort of patients with advanced cancer who grapple with existential dread due to the uncertainty of their prognosis. If psychedelics can alleviate this existential burden, these patients may find a greater sense of peace and joy in their remaining life. The authors plan to conduct a trial in 2024 to explore this possibility, and despite a conservative majority, they are optimistic about gaining approval from the Texan legislature, which shows openness to psychedelic research.

COMPASS Pathways Announces Positive Results From Their Phase 2 Trial assessing Synthetic Psilocybin COMP360 Alongside SSRIs for Treatment-Resistant Depression

COMPASS Pathways Announces Positive Results From Their Phase 2 Trial assessing Synthetic Psilocybin COMP360 Alongside SSRIs for Treatment-Resistant Depression

Positive Data From COMPASS Pathways’ Phase 2 Trial Combining Psilocybin & SSRIs

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