The 3,4-methylenedioxymethamphetamine enhances early visual processing for salient socio-emotional stimuli

The 3,4-methylenedioxymethamphetamine (MDMA) has long been used non-medically, and it is currently under investigation for its potential therapeutic benefits. Both uses may be related to its ability to enhance empathy, sociability, emotional processing and its anxiolytic effects. However, the neural mechanisms underlying these effects, and their specificity to MDMA compared to other stimulants, are not yet fully understood. Here, using electroencephalography (EEG), we investigated the effects of MDMA and a prototypic stimulant, methamphetamine (MA), on early visual processing of socio-emotional stimuli in an oddball emotional faces paradigm. Specifically, we examined whether MDMA or MA enhance the processing of facial expressions, compared to placebo, during the early stages of visual perception. MDMA enhanced an event-related component that is sensitive to detecting faces (N170), specifically for happy and angry expressions compared to neutral faces. MA did not affect this measure, and neither drug altered other components of the response to emotional faces. These findings provide novel insights into the neural mechanisms underlying the effects of MDMA on socio-emotional processing and may have implications for the therapeutic use of MDMA in the treatment of social anxiety and other psychiatric disorders. The study investigated the effects of 3,4-methylenedioxymethamphetamine (MDMA) and MA compared to placebo on emotional processing in healthy adults. MDMA, but not methamphetamine (MA), increased the N170 peak amplitude in response to happy and angry faces compared to neutral faces, indicating enhanced early visual processing of socially salient stimuli. Both drugs increased subjective feelings associated with drug liking and wanting more, but only MA increased feelings of sociability. Neither drug affected cognitive processing as measured by P300 or mismatch negativity (MMN) evoked potentials. image