3,4-methylenedioxymethamphetamine (MDMA) is a potent monoamine releaser that produces an acute euphoria in most individuals.
MDMA was orally administered to 25 physically and mentally healthy individuals in a double-blind, placebo-controlled, balanced-order study. Arterial spin labelling (ASL) and seed-based resting state functional connectivity (RSFC) were used to produce spatial maps displaying changes in cerebral blood flow (CBF) and RSFC after MDMA. Participants underwent two ASL and two BOLD scans in a 90 minute scanning session and the MDMA and placebo study days were separated by one week.
MDMA produced marked increases in positive mood. Only decreased CBF was observed after MDMA and this was localised to the right medial temporal lobe (MTL), thalamus, inferior visual cortex and the somatosensory cortex. Decreased CBF in the right amygdala and hippocampus correlated with ratings of the intensity of MDMA’s global subjective effects. The RSFC results complemented the CBF results, with decreases in RSFC between midline cortical regions, the medial prefrontal cortex and MTL regions, and increases between the amygdala and hippocampus. There were trend-level correlations between these effects and ratings of intense and positive subjective effects.
The MTLs appear to be specifically implicated in the mechanism of action of MDMA but further work is required to elucidate how the drug’s characteristic subjective effects arise from its modulation of spontaneous brain activity.
Carhart-Harris, R. L., Murphy, K., Leech, R., Erritzoe, D., Wall, M. B., Ferguson, B., … Nutt, D. J. (2014). The Effects of Acutely Administered 3,4-Methylenedioxymethamphetamine on Spontaneous Brain Function in Healthy Volunteers Measured with Arterial Spin Labelling and Blood Oxygen Level-Dependent Resting-State Functional Connectivity. Biological Psychiatry. http://dx.doi.org/10.1016/j.biopsych.2013.12.015