In a development that’s turning heads across the medical and scientific communities, a new clinical trial published in the Journal of the American Medical Association (JAMA) on September 4, 2025, has found that a single dose of the psychedelic drug LSD may significantly reduce symptoms of generalized anxiety disorder (GAD) for months. The study, sponsored by the biotechnology company MindMed, is being hailed as a potential turning point in the ongoing search for more effective treatments for anxiety—a condition that affects nearly 3% of U.S. adults, according to the National Institutes of Health.
Generalized anxiety disorder is notoriously difficult to treat. While medications like benzodiazepines and selective serotonin reuptake inhibitors (SSRIs) are commonly prescribed, up to half of patients don’t see adequate improvement with these first-line therapies. This leaves a large population searching for alternatives that are both effective and well-tolerated. Now, with the resurgence of interest in psychedelic medicine, LSD is making a dramatic comeback after decades in the shadows.
The phase II trial, as reported by Live Science and other outlets, involved 194 to 198 people diagnosed with moderate to severe anxiety, recruited from across the United States. Participants were randomly assigned to receive a placebo or one of four doses of LSD—25, 50, 100, or 200 micrograms (also referred to as milligrams in some reports, though micrograms is the standard measure for LSD). After a single, supervised dose, participants were closely monitored for 12 hours and then tracked for a total of 12 weeks to assess changes in their anxiety symptoms.
The results were striking. By the fourth week, participants who received either 100 or 200 micrograms of LSD reported significantly greater reductions in anxiety compared to those on placebo or lower doses. The most dramatic improvements were seen in the 100-microgram group: 12 weeks after treatment, about 47% were considered in remission—a score of 7 or less on the standardized anxiety scale used—while 65% saw their anxiety scores cut by at least half. In contrast, only about 20% of the placebo group achieved remission, and 30% saw their scores halved.
“This study is a true turning point in the field of psychiatry,” said Dr. Maurizio Fava, chair of the department of psychiatry at Mass General Brigham and MindMed scientific advisor, in a statement reported by Live Science. Fava, who also served as the study’s lead author, added, “It’s possible that some people may need retreatment. How many retreatments, we don’t know yet, but the long-lasting effect is quite significant.”
The trial’s design was particularly notable for its attempt to isolate the effects of LSD itself, rather than combining the drug with psychotherapy as in many previous studies of psychedelics. Only 18% of participants were receiving ongoing external therapy, and the study did not incorporate structured talk therapy as part of the protocol. This approach aimed to answer a key question: does LSD alone have a clinically meaningful anti-anxiety effect, or is its benefit tied to the therapeutic context in which it’s administered?
Dr. Claudio Soares, professor of psychiatry at Queen’s University School of Medicine in Ontario, wrote in a commentary that the study “has the potential to make significant contributions to the emerging field of psychedelic drug research.” He highlighted the early response to treatment and positive effects on comorbid depressive symptoms as particularly promising findings that should guide future research. “The study highlighted an early response to treatment and positive effects on comorbid depressive symptoms, both of which are promising findings that should guide future trials,” Soares said.
Of course, as with any powerful drug, side effects were part of the picture. The most common included visual hallucinations or distortions, nausea, headaches, and feelings of euphoria. Nearly everyone who took a 100-microgram or higher dose experienced some form of visual change. While most side effects were mild to moderate and resolved after the drug wore off, a handful of participants did drop out of the trial because of these experiences, meaning LSD may not be suitable for all patients. Notably, side effects were reported in the placebo group as well, though at much lower rates.
The trial was not without its limitations. Most notably, many participants correctly guessed whether they had received LSD or a placebo, potentially introducing bias and undercutting the “blinded” approach that is the gold standard in clinical research. Additionally, a significant portion of participants in both groups dropped out early, narrowing the final data set. The follow-up period was limited to just three months, leaving questions about the durability of LSD’s effects over longer timescales.
Still, the findings are encouraging enough that MindMed has already launched three large phase III trials of its proprietary LSD formulation, MM-120, for both anxiety and depression. These late-stage trials, which will track patients over a longer period, are designed to provide the robust evidence needed for the Food and Drug Administration (FDA) and other regulators to consider LSD as a legitimate treatment for anxiety. Results from these studies are expected in 2026.
The path to regulatory approval for psychedelics has been anything but straightforward. As The Associated Press noted, the FDA has previously granted “breakthrough therapy” status to other psychedelics like psilocybin and MDMA, but also rejected MDMA-assisted therapy for post-traumatic stress disorder (PTSD) in 2024, citing flaws in study design and the need for more data. Nevertheless, the agency has shown willingness to fast-track promising treatments, especially for conditions like GAD that are difficult to treat with existing medications.
The renewed scientific interest in LSD marks a return to research that was largely abandoned in the late 1960s, when the drug became associated with countercultural figures like Timothy Leary and was classified as a Schedule 1 substance—deemed to have no medical use and a high potential for abuse. “LSD was right there in front of everybody, but Mindmed is the first company that actually decided to evaluate it,” Fava told AP. In the 1950s and 1960s, more than a thousand papers were published on LSD’s therapeutic use for conditions ranging from alcoholism to depression, but the federal backlash of the 1970s effectively ended mainstream research for decades.
As the debate over psychedelic medicine continues, voices on all sides are weighing in. Supporters see the new findings as a long-overdue validation of psychedelics’ potential, while skeptics caution that the drugs’ mind-altering effects and the challenges of proper trial design mean there’s still much to learn. The trial’s authors themselves stress that more research is needed—particularly to determine how long the benefits last and whether repeated dosing is safe and effective.
For now, the results offer hope to millions living with anxiety that new, more effective treatments could be on the horizon. As phase III trials get underway and regulators take a closer look, the story of LSD’s return to the medical mainstream is far from over.
