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.
Psychopharmacology
February 1, 2026
Ana Deutsch, Connor J Haggarty, Gavin N Petrie et al.
1 citation
A single oral dose of methamphetamine (20 mg) reduced blood levels of the endocannabinoid 2-AG in healthy adults, while MDMA (100 mg) did not. Neither drug affected anandamide (AEA) levels. Under placebo, higher AEA concentrations were linked to disliking the drug effects, suggesting a connection between AEA and negative expectations. These findings show how stimulants act on the endocannabinoid system and may inform treatments for substance use disorders.
The European journal of neuroscience
June 1, 2024
Connor J Haggarty, Anya K Bershad, Mahesh K Kumar et al.
1 citation
MDMA, but not methamphetamine, enhances the brain's early visual processing of happy and angry facial expressions, as measured by the N170 event-related potential in an EEG oddball paradigm. This effect was specific to emotional faces compared to neutral ones. Methamphetamine did not affect this neural measure, and neither drug altered other components of the response to emotional faces. The findings suggest a unique neural mechanism for MDMA's effects on socio-emotional processing, which may underlie its therapeutic potential for social anxiety and other psychiatric disorders.