In a development that could upend the treatment landscape for anxiety disorders, a landmark clinical trial has found that a single dose of LSD can provide months-long relief from generalized anxiety disorder (GAD) — and all without the need for traditional talk therapy. The study, conducted by the biotech company MindMed and published in the Journal of the American Medical Association on September 5, 2025, signals a possible renaissance for psychedelics in psychiatric care after decades of legal and cultural prohibition.
The trial enrolled 198 adults aged 18 to 74, all diagnosed with moderate to severe GAD. Participants were randomly assigned to receive one of four LSD dosages — 25, 50, 100, or 200 micrograms — or a placebo. Each treatment was administered under clinical supervision, but notably, no psychotherapy accompanied the dosing session. Instead, participants were monitored in private, aesthetically pleasant rooms, with standardized music and eyeshades provided to help shape the experience. Two dosing session monitors oversaw each participant, ensuring safety and support throughout the process.
The results were nothing short of striking. According to MindMed’s data, those who received the higher doses of LSD — specifically 100 or 200 micrograms — began reporting significant reductions in anxiety symptoms within just 24 hours. "By the next day, they were showing strong improvements," Dr. David Feifel of the Kadima Neuropsychiatry Institute, one of the study’s 22 participating centers, told NPR. These improvements not only persisted but actually increased by the fourth week, dramatically outpacing both the lower-dose and placebo groups.
At the 12-week mark, the numbers told a compelling story: around 65% of patients treated with the 100-microgram dose continued to benefit, and nearly half had achieved full remission from their anxiety symptoms. Depression scores also improved notably in this group, an effect not seen in those receiving lower doses or placebo. The study’s lead author, Dr. Maurizio Fava of Mass General Brigham Hospital, emphasized the potential significance: "How many retreatments, we don’t know yet, but the long-lasting effect is quite significant."
Safety, always a key concern in psychiatric drug development, was rigorously monitored. The most common side effects were hallucinations, nausea, and headaches. Importantly, there were no incidents of self-harm or suicidal behavior among participants. "The safety looks good, the tolerability looks good," Robin Carhart-Harris, a psychedelics researcher at the University of California, San Francisco, who was not involved in the study, told NPR. Still, he and others noted that the study’s description of environmental and psychological supports was limited, making it difficult to disentangle the drug’s effects from those of the setting and support provided.
The trial’s design also raised questions about blinding, a critical component in drug research. Many participants could correctly guess whether they had received LSD or a placebo, a challenge that has long dogged psychedelic studies. This awareness may have influenced the outcomes, potentially amplifying the placebo effect. Additionally, a significant portion of patients in both the placebo and treatment groups dropped out early, narrowing the final dataset and raising questions about the generalizability of the findings.
Nevertheless, MindMed’s study represents a major leap forward in the rigorous evaluation of psychedelics for mental health. The proprietary LSD formulation used in the trial, known as MM120, is now the subject of two large Phase 3 trials, which the company expects to complete in 2026. The U.S. Food and Drug Administration (FDA) has already granted MM120 “breakthrough therapy” status, a designation intended to accelerate the review process for drugs showing promise in treating serious conditions. This places LSD alongside other psychedelics like psilocybin and MDMA, which have also received similar designations for their potential in treating depression and post-traumatic stress disorder, respectively.
The resurgence of interest in LSD as a therapeutic agent is especially notable given its fraught history. In the 1950s and 1960s, more than 1,000 papers were published exploring LSD’s potential for treating conditions ranging from alcoholism to depression. However, the association of psychedelics with counterculture figures like Timothy Leary and the subsequent federal crackdown — culminating in the 1970 classification of LSD as a Schedule 1 drug — brought research to a near halt. For decades, the scientific community steered clear of LSD, focusing instead on less controversial hallucinogens such as MDMA and psilocybin.
MindMed’s decision to revisit LSD’s therapeutic potential marks a turning point. "LSD was right there in front of everybody, but MindMed is the first company that actually decided to evaluate it," Dr. Fava told the Associated Press. The company’s willingness to subject LSD to the rigors of modern clinical research — and its success in doing so — has drawn praise from experts across the field. Frederick Barrett, director of Johns Hopkins University’s psychedelic center, commented, "I see this paper as a clear step in the direction of reviving that old research, applying our modern standards and determining what are the real costs and benefits of these compounds."
Generalized anxiety disorder is among the most common mental health conditions, affecting nearly 3% of U.S. adults according to the National Institutes of Health. The disorder is characterized by chronic, excessive worry that interferes with daily functioning and is often accompanied by physical symptoms like racing heart rates and sweating. Current treatments — including psychotherapy, antidepressants, and anti-anxiety medications such as benzodiazepines — are inadequate for about half of those diagnosed, leaving a substantial gap in care.
The implications of MindMed’s findings could be far-reaching. Health officials in the current U.S. administration, including Health Secretary Robert F. Kennedy Jr., have expressed interest in fast-tracking psychedelic therapies for veterans and others suffering from psychological trauma. If the ongoing Phase 3 trials confirm the results seen so far, LSD could become the first new drug approved for GAD since 2007 — a potential watershed moment for both psychiatry and drug policy.
Yet, questions remain. The durability of LSD’s effects, the necessity and frequency of retreatment, and the optimal balance between drug and non-drug factors all require further investigation. As Carhart-Harris put it, "A whole mindset shift is going to happen around that." For now, the study stands as a milestone in the long and winding journey of psychedelics from the fringes of medicine back into the mainstream.
