A recent study has found that specialized psychotherapy paired with doses of either LSD or psilocybin is associated with strong reductions in severe depression and anxiety. These mental health improvements emerged relatively quickly and took place within a standard hospital care program. The findings were published in the journal Psychiatry Research.
In recent years, researchers have renewed their investigation into the medical potential of classic hallucinogens. Conditions like severe depression and generalized anxiety do not always respond to standard psychiatric medications. For many individuals, initial treatments such as selective serotonin reuptake inhibitors fail to provide lasting relief from persistent sad moods or chronic worry.
Individuals who do not respond to multiple standard treatments are often diagnosed with treatment-resistant conditions. This status leaves them with limited options in conventional medical practice. Psychedelic-assisted therapy has emerged as a promising alternative for these populations in strictly monitored experimental trials.
These therapies combine traditional talk therapy with the ingestion of a mind-altering substance under professional supervision. The goal is to induce a temporary change in consciousness that allows patients to process difficult emotions. A trained therapist helps the patient integrate these conceptual insights into their daily life after the drug effects wear off.
Most of the current evidence for these treatments comes from randomized controlled trials. While these trials offer rigorous baseline data, they often exclude patients with varied medical histories to isolate a specific chemical variable. This strict filtering means the results do not always translate perfectly to general hospital populations.
To understand how these treatments perform outside of rigid experiments, researchers look to compassionate use programs. These legal frameworks allow doctors to administer unapproved, experimental medications to patients who have exhausted all other available therapies. Switzerland operates one such framework, giving doctors restricted authorization to use specialized substances for severe mental health cases.
Tatiana Aboulafia-Brakha, a researcher at the Geneva University Hospitals, led an effort to analyze data from one of these Swiss clinical programs. Aboulafia-Brakha and her team wanted to evaluate the outcomes of patients receiving these therapies in a routine hospital setting. They sought to document changes in mental health symptoms and to record how well patients tolerated the experience.
The team collected retrospective data from a cohort of adults diagnosed with treatment-resistant depressive or anxiety disorders. This cohort underwent their first standardized treatment cycle between May 2024 and October 2025. Each individual received either 100 micrograms of LSD or 25 milligrams of psilocybin during their session.
Psilocybin is the primary psychoactive compound found in certain species of hallucinogenic mushrooms. LSD is a synthetic chemical known for producing potent shifts in perception and thought patterns. Patients were allowed to choose their preferred substance based on personal comfort, anticipated session length, and cost.
The program required extensive preparation before the actual administration of the drug. Patients attended screening sessions to review their medical histories and ensure no underlying heart or neurological conditions existed. They also engaged in preparatory meetings to set therapeutic intentions and learn coping strategies like breathing exercises for managing acute moments of fear.
On the day of the treatment, patients arrived at an outpatient clinic and settled into a quiet room under the constant supervision of psychiatric nurses. The nurses monitored vital signs and intervened only if the patient requested support or required help navigating a challenging psychological reaction. The patients then remained in the clinic until the acute subjective effects had completely resolved.
Patients returned the following day for an integration session with a psychotherapist. During this conversation, patients discussed the imagery, body sensations, and emotional revelations they experienced while receiving the drug. The therapist then helped them translate those abstract insights into actionable behavioral routines.
To quantify the results, the researchers administered standard psychological questionnaires at three distinct points in time. Patients filled out surveys during their initial screening, one month before the treatment, and one to three months after the session. These tools measured the severity of general sadness, pessimism, and habitual stress responses.
The team observed a pronounced decrease in both depression and anxiety scores over the treatment timeline. More than a third of the sample reported that their depressive symptoms had been reduced by at least half. A smaller portion recorded modest but noticeable symptom relief. These benefits appeared robust across the broader cohort, supporting previous findings from highly controlled laboratory environments.
The choice of substance did not seem to alter the long-term therapeutic outcome. Patients who took LSD and those who took psilocybin experienced largely identical improvements in their daily mental health.
Aboulafia-Brakha and her team also investigated how patients managed their emotions before and after the treatments. A subset of the patients completed an emotion regulation survey measuring strategies like rumination and catastrophizing. Rumination involves repetitively dwelling on negative feelings, while catastrophizing is a tendency to expect the worst possible outcome in any situation.
Following the therapy, patients reported large reductions in their tendencies to ruminate, catastrophize, and blame themselves for negative life events. They also demonstrated an increased capacity for positive reappraisal, which means they could more easily find a constructive perspective in difficult situations. These conceptual shifts align with psychological theories that consider rigid thinking to be a primary maintenance factor for severe depression.
While the long-term clinical benefits were similar across both substances, the acute physical experiences differed notably. The data indicated that LSD produced a longer, sustained plateau of intense subjective effects. Psilocybin caused a similar peak of intensity, but the overall duration of the psychoactive experience was noticeably shorter.
Despite these differing timelines, the overall intensity of the mystical experiences reported by the patients was roughly equivalent. Questionnaires measuring profound feelings of unity, distinct alterations in time perception, and deep spiritual insight yielded similar scores. These outcomes support the concept that the subjective journey might matter more than the specific pharmacological timeline.
Safety evaluations showed that both substances were well tolerated within the hospital environment. Many patients reported no adverse reactions at all, while the majority of recorded side effects were mild and temporary. The most common physical complaints included transient blurred vision, dizziness, and mild nausea during the active phase of the medication.
The team recorded no serious medical complications or severe psychiatric emergencies during the study period. No patient discontinued the treatment due to an adverse reaction. These details provide reassuring baseline evidence for medical professionals worried about introducing potent hallucinogens into general outpatient clinics.
This study has a few limitations due to its retrospective design and observational nature. The researchers did not include a placebo group, which means they cannot entirely rule out the influence of patient expectations. Patients who pursue rigorous medical treatments often expect to feel better, and this hope can artificially inflate self-reported symptom relief.
The cohort was highly motivated, considering the long waiting times and financial costs associated with the compassionate use program. This unique determination among the participants might mean the results would be different in a less motivated patient population. The reliance on self-reported questionnaires also leaves room for memory biases to influence the data.
Future studies will need to implement randomized designs involving active placebos to better isolate the specific physiological effects of the therapy. Combining patient self-reports with objective evaluations from independent clinicians could ensure a more reliable assessment of long-term improvement. Until then, these findings offer an encouraging glimpse into the practical realities of psychedelic therapies in standard psychiatric settings.
The study, “Real-world effectiveness and safety of psychedelic-assisted psychotherapy: Outcomes from a large-scale compassionate use cohort in Switzerland,” was authored by T. Aboulafia-Brakha, A. Buchard, C. Mabilais, S. Alaux, C. Amberger, L. Furtado, F. Seragnoli, J-F Briefer, G. Thorens, M. Sabé, L. Szczesniak, R. Iuga, D. Zullino, and L. Penzenstadler.
