Response to the Lykos CRL; How big does an LSD dose need to be to quell anxiety?; and Psilocybin-assisted therapy results, 5 years later
The Latest from Oregon, and Optimi Health files IPO
Happy Friday and welcome back to The Microdose, an independent journalism newsletter brought to you by the U.C. Berkeley Center for the Science of Psychedelics.
Response to the Lykos CRL
Last week, the U.S. Department of Health and Human Services released a batch of previously unpublished complete response letters (CRLs), including the one the U.S. Food and Drug Administration sent to Lykos Therapeutics explaining the agency’s decision not to approve MDMA as a drug for treating PTSD. In the days since, psychedelics advocates and insiders have weighed in on what the letter might mean about the future of psychedelic medicalization in the country. Rick Doblin, co-founder of MAPS, the non-profit that initiated the MDMA clinical trial process before spinning its endeavors out into Lykos, issued a statement commending Marty Makary, the FDA commissioner, and HHS secretary Robert F. Kennedy Jr. for releasing the letter, which had not been made public despite repeated requests from advocates and journalists. “But let’s be clear,” Doblin said. “The CRL reveals a devastating truth — the FDA moved the goalposts.” Doblin writes that the FDA approved MAPS’s Phase 3 clinical trial design, and only changed its standards after the trials were complete.
“There were problems with the application and studies,” Matthew Johnson, a psychedelic researcher at Sheppard Pratt, wrote on X. “But it seems that the reasons above didn’t require rejection, but rather a solid REMS and additional data before broader treatment (i.e., no retreatment until more durability/retreatment data).” REMS, or a Risk Evaluation and Mitigation Strategies (REMS) notification, is a series of recommendations the FDA issues to a medication prescriber about how to safely use the medicine.
“While the decision is a clear setback for the field, it also provides a roadmap for getting things right the next time,” wrote Berra Yazar-Klosinski, who served as Lykos’s Chief Scientific Officer throughout the company’s FDA application until this summer, on LinkedIn. Yazar-Klosinski has now launched her own consulting business advising companies on aspects of study design, including actions designed to address “lessons from the Lykos CRL,” such as holding mock panels and “data story refinement” in preparation for advisory committee meetings.
In the year since the FDA’s decision, many psychedelic activists and supporters have speculated about the factors underlying it — and some have blamed Psymposia, a psychedelics watchdog organization that has raised concerns about abuse in psychedelic therapy and in psychedelic clinical trials, including MAPS’s Phase 2 MDMA trial. The FDA’s CRL mentions neither the group nor its members, but does note that the agency’s review of Lykos’s data uncovered previously unreported adverse events. Some saw that as proof that Psymposia had not, in fact, caused the FDA rejection. “While we've been harassed, MAPS/Lykos supporters have known FOR A YEAR that they were pushing a false narrative that scapegoated us for the FDA's rejection of MDMA,” wrote Psymposia member and Johns Hopkins senior lecturer Neşe Devenot on X.
How big does an LSD dose need to be to quell anxiety?
Large doses of LSD could help quell anxiety symptoms, according to a new study published in JAMA by researchers affiliated with psychedelics company MindMed. In the trial, 194 participants with moderate to severe anxiety, as measured by a standard anxiety rating scale, were randomly assigned to receive a single dose of MM120, the company’s formulation of LSD, or an inactive placebo. Doses were 25 micrograms or μg (thought to be on the cusp of a perceptible dose), 50 μg, 100 μg, or 200 μg. (For reference, when Albert Hofmann famously first synthesized LSD and tried to ride his bicycle home, he ingested approximately 250 μg.)
Four weeks later, participants completed the same anxiety rating scale. Groups that had received the larger doses of MM120 — 100 and 200 μg — showed a statistically significant decrease in symptoms compared to those in the placebo group, but that was not the case for the 25 and 50 μg dose groups. Participants reported mild to moderate adverse effects during their dosing session, including visual hallucinations or bodily sensations. The authors write that while three participants experienced severe adverse effects, including suicidal ideation, "no participants engaged in self-injurious or suicidal behavior.” Overall, the authors write that the 100 μg dose is “optimal”: it was associated with lowered anxiety symptoms as well as mild to moderate adverse effects.
Most notably, this study did not include any therapy. Participants were monitored for safety during dosing sessions, though some participants were already seeing therapists. “For this specific clinical study, it was vital to assess a drug-only effect for regulatory purposes. This also helps ensure that in the future, if MM120 is approved, there is potential for a wide range of treatment environments,” Maurizio Fava, psychiatrist-in-chief at Mass General Hospital and one of the study’s authors, told The Microdose. “These results show the potential of LSD as a stand-alone treatment, and I'm very encouraged by them.” But even if this study did not use psychotherapy, Fava noted that it is not incompatible with MM120 treatment, writing that “psychotherapy can be an important tool to further support an individual’s mental health and clinicians should determine if there is a need on a case-by-case basis with their patients.”
Want the latest psychedelics news? Subscribe! (It’s free!)
Psilocybin-assisted therapy results, 5 years later
The resurgence of psychedelic research is still relatively new — which means researchers have little data on the long-term effects of psychedelic-assisted therapy. In a new study published in Journal of Psychedelic Studies, researchers at Johns Hopkins and The Ohio State University followed up with participants in a psilocybin-assisted therapy for major depressive disorder clinical trial five years after they first received treatment.
The initial study included 24 participants, who were randomized to either immediately begin treatment or be put on a waiting list, where they would receive treatment 8 weeks later. During treatment, participants underwent two psilocybin sessions as well as around 11 hours of psychotherapy. At week 5 of the study, when those in the immediate treatment group had already undergone their treatment and those in the delayed treatment group were still waiting for treatment, those who’d received psilocybin had significantly lower depression scores than those in the delayed treatment group. After those in the delayed treatment group received psilocybin, they, too, showed a decrease in depression scores. When researchers followed up with the participants a year later, 18 of the 24 participants showed an enduring response to treatment and 14 were in remission from depressive symptoms.
At the five year follow-up, 18 of the 24 participants completed the study; the researchers used previous baseline scores as a “conservative estimate” for outcomes from the six participants who did not participate. With that data, the researchers found that 67% of participants were in remission. But the authors acknowledge that psilocybin-assisted therapy is unlikely to be the only factor in those participants’ remission. “For example, 11 participants (61%) reported in the qualitative interviews that they started a daily antidepressant medication at some point during the [long-term follow-up], though only seven were currently taking these medications,” they write. Some participants also felt “an altered relationship with their depressive symptoms, noting greater acceptance of difficulties and symptoms, even amidst recurrence.”
The Latest from Oregon
Oregon Psilocybin Services announced this week that it has released new data on the number of dosing sessions and client demographics collected in the state between April 1 and June 30 of this year. OPS’s data dashboard displays a comprehensive range of information about the program. Highlights include:
A total of 1758 clients served in Q2 of 2025, 1424 of which were served in individual sessions and 211 in group sessions. Of all those sessions, just four clients — 0.002% — experienced adverse effects severe enough to involve emergency services.
62 people were denied psilocybin services, most because they did not meet eligibility requirements. Two were denied for exhibiting “concerning behaviors.”
Since the program’s inception in 2023, it has sold 31,444 psilocybin products totalling $1.5 million — a small drop in the bucket compared to the state’s $621 million in cannabis sales in 2025 so far.
In the second quarter of 2025, 1089 people who responded to a question in the client demographic survey about where they live. A sizable chunk — 16% —reported they did not want to answer. Oregonians made up 29% of the total respondents while 41% were from out of state, and 13% from out of the country.
The state also includes all letters they’ve sent to licensees regarding license application denials, license suspensions and rules violations. Some violations, like the failure of four psilocybin service centers to submit quarterly data, resulted in civic fines of $500. Another letter revoked the license of a facilitator who allegedly violated a rule not to engage in a romantic or sexual relationship with clients or their families. Additionally, a service center was fined $3000 for allegedly leaving clients alone during the administration for “more than five minutes.”
Optimi Health files IPO
On Monday, Canadian psilocybin and MDMA manufacturer Optimi Health announced that they had filed an initial public offering (IPO) statement with the U.S. Securities and Exchange Commission to raise up to $25 million. The filing was submitted last Friday, and estimates that the company “can supply up to 100,000 PTSD patients (36,000g - 54,000g of MDMA) with MDMA therapy and 200,000 treatment-resistant depression (10,000g - 15,000g of psilocybin) patients with psilocybin therapy annually.”
Four men hiking in New York’s Catskill Mountains called emergency services after one experienced a “debilitating high” and another hallucinated a bridge that didn’t exist. The group got lost just 1,000 feet from the trail. “I’m not an expert in mushrooms, but these gentlemen definitely rode highs and lows,” Russell Martin, one of their rescuers, told The New York Times.
Psychedelic Alpha reports that Cybin has ousted its CEO Doug Drysdale.
“The fact that Drysdale isn’t quoted in the release, and that there is no replacement CEO lined up, makes it clear that he was not party to the decision,” writes Josh Hardman.Joseph Emerson, the off-duty Alaska Airlines pilot who in 2023 tried to shut off a plane’s engine mid-flight, pled guilty this week to dozens of Oregon state reckless endangerment counts, as well as a federal charge for interfering with flight crew members and attendants, reports The Seattle Times. Shortly after the incident, Emerson told investigators that he had taken psychedelic mushrooms about 48 hours before the incident in an effort to treat his depression — and that it was the first time he’d ever tried them.
For some people, psychedelics have led to a more fluid understanding of their gender and sexuality, reports Mattha Busby for States of Mind.
Dozens of professional athletes have now publicly discussed their use of psychedelics. WIRED covers the substances’ popularity among NFL stars.
You’re all caught up! We’ll be back in your inbox on Monday with a new issue of 5 Questions.
If you know anyone who might like the latest on psychedelics in their inbox, feel free to forward this to them, or click below.
Got tips? Email us at themicrodose@berkeley.edu.
