In an open-label phase 2A trial, 19 participants with major depressive disorder, most of whom were taking antidepressants, took microdoses of LSD twice weekly for eight weeks. No serious adverse events occurred, and one participant withdrew due to anxiety. Depression scores on the Montgomery-Åsberg Depression Rating Scale dropped by 59.5% at the end of the intervention, with improvements sustained for up to six months. Anxiety, rumination, stress, and quality of life also improved. The results provide preliminary evidence that microdosed LSD is safe and feasible for treating moderate depression, but randomized controlled trials are needed.
After a six-week double-blind placebo-controlled trial of 10 µg of lysergic acid diethylamide taken every third day, healthy male participants reported changes in emotions, mood, social life, mindfulness, cognition, work, creativity, and physiological effects. Openness to experience and bidirectionality of effects were overarching themes. Some reported changes have potential clinical relevance for mood disorders, and reports of changes in anxiety suggest careful patient and dose selection. Participants' experiences with set and setting, uncertainty from placebo control, and perceived bidirectionality of effects inform psychedelic clinical trial design.