722. Predictors of therapeutic response to LSD in anxiety: short- and long-term outcomes
Friederike Holze, F Müller, Peter Gasser, M Liechti
International Journal of Neuropsychopharmacology September 9, 2026 DOI: 10.1093/ijnp/pyag040.494 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Randomized controlled trial Placebo-controlled Double-blind Peer reviewed |
|---|---|
| Population | Patients with anxiety with or without life-threatening illness |
| Intervention | LSD |
| Dose | 200 μg |
| Duration | 24 weeks per period (48 weeks total), with follow-up up to 1 year after the end-of-study visit |
| Measures | Spielberger’s State-Trait Anxiety Inventory–Global (STAI-G), Persisting Effects Questionnaire (PEQ), 5 Dimension Altered State of Consciousness Questionnaire (5D-ASC), 30-item Mystical Effects Questionnaire (MEQ30) |
| Topics | Anxiety LSD |
| Key findings | Positive acute subjective drug effects (Oceanic Boundlessness) and mystical-type experiences (MEQ30) correlated with short-term anxiety reductions 16 weeks after the last LSD session (r = -0.40 and r = -0.34) and with long-term reductions at one year (r = -0.33 and r = -0.34). Negative acute effects (Anxious Ego Dissolution) showed no correlation with therapeutic outcomes. The authors conclude that positive acute effects and mystical-type experiences predict short- and long-term therapeutic outcomes. |
Abstract
Abstract Background Anxiety disorders are a major health burden and current treatment options yield unsatisfactory results. Psychedelics, such as lysergic acid diethylamide (LSD) that act via agonism on serotonin 2A receptors, have recently been shown to be effective in the treatment of anxiety symptoms. Aims & Objectives Here, we determine the relationship between the acute experience and short and long-term outcomes of in patients who suffered from anxiety with or without life-threatening illness.
Method: This study was an investigator-initiated two-center trial that used a double-blind, placebo-controlled, two-period, random-order, crossover design with two sessions with either oral LSD (200 μg) or placebo per period separated by 6 weeks. The study duration was 24 weeks per period (48 weeks total) and patients were followed up to 1 year after the end-of-study visit of the original trial. The primary endpoint was assessed 16 weeks after the last treatment session. We assessed symptoms of anxiety and long-term effects of psychedelics using Spielberger’s State-Trait Anxiety Inventory–Global (STAI-G) and the Persisting Effects Questionnaire (PEQ). Furthermore, acute drug effects were assessed using the 5 Dimension Altered State of Consciousness Questionnaire (5D-ASC) and the 30-item Mystical Effects Questionnaire (MEQ30).
Results: On the STAI-G, positive acute subjective drug effects measured with the 5D-ASC (Oceanic Boundlessness [OB]) and mystical-type experiences (MEQ30 total score) correlated with short-term reductions (16 weeks after last treatment) in anxiety symptoms (r = -0.40, p = 0.01 and r = - 0.34, p = 0.03, respectively) and also long-term reductions (1-yr follow-up; r = -0.33, p = 0.055 and r = - 0.34, p = 0.048, respectively). Negative subjective drug effects (Anxious Ego Dissolution [AED]) showed no correlations with therapeutic outcomes. On the PEQ, assessed at 1yr-follow-up, OB and the MEQ30 total score correlated significantly with “positive attitudes about life and/or self” (p = 0.035 and p = 0.015, respectively) and “positive mood changes” (p = 0.015 and p = 0.005, respectively). AED scores did not correlate significantly with long-term outcomes on the PEQ. Discussion & Conclusions Summarized, these findings indicate that acute positive drug effects and mystical-type experiences predict short and long-term therapeutic outcomes, while acute negative drug effects remain neutral.