Psychopharmacology
October 6, 2021
Conor H. Murray, Ilaria Tare, Claire Perry et al.
75 citations
Low doses of LSD (13 and 26 micrograms) produced broad reductions in brain wave power across multiple frequency bands during rest and dampened specific event-related potentials (P300 and N170) during a visual task in healthy adults. The drug also increased positive mood, energy, and anxiety, as well as heart rate and blood pressure, but did not cause the full perceptual or sensory changes typical of higher psychedelic doses. These neurophysiological effects resemble those seen with higher doses, suggesting that very low LSD doses might produce subtle behavioral or therapeutic effects without inducing a full psychedelic experience.
Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology
April 1, 2024
Hanna Molla, Royce Lee, Ilaria Tare et al.
37 citations
A single low dose of LSD (26 µg) produces more pronounced positive mood effects and stronger altered states of consciousness in people with mild depressive symptoms than in those without. In a randomized, double-blind, crossover trial, 39 adults received either LSD or placebo. Those scoring 17 or higher on the Beck Depression Inventory reported greater increases in vigor, elation, and positive psychedelic effects, and showed a larger decline in depression scores 48 hours after the dose, compared with placebo. The drug caused only mild physiological and subjective effects overall.
Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology
June 1, 2024
Conor H Murray, Joel Frohlich, Connor J Haggarty et al.
30 citations
Neural complexity, a measure of brain signal diversity, increases after low doses of LSD (13 and 26 µg) even when volunteers do not report an altered state of consciousness. In three separate placebo-controlled experiments with 73 healthy adults, LSD dose-dependently raised neural complexity, while THC and methamphetamine did not. LSD also reduced delta and theta brain wave power, and those reductions correlated with feelings of elation. THC reduced alpha power, which was linked to altered states, and methamphetamine increased alpha power. The findings show that increased neural complexity is neither necessary nor sufficient for an altered state of consciousness, and that different drugs affect brain activity and subjective experience through distinct mechanisms.
Psychedelic medicine (New Rochelle, N.Y.)
December 1, 2024
Connor Haggarty, Hanna Molla, James Glazer et al.
2 citations
A low dose of LSD (26 µg) alters the brain's electrical response to neutral and happy faces, but not angry faces. In a double-blind, placebo-controlled experiment with 39 healthy adults, LSD reduced the amplitude of the N170 brain wave to neutral faces and reduced the P300 brain wave to neutral and happy faces, while angry faces were unaffected. These results suggest that low-dose LSD specifically changes how the brain processes non-threatening social cues, which may help explain reports of improved mood.