Ecstasy has the potential to be an effective treatment for anxiety and post-traumatic stress disorder (PTSD), experts have said.
For the first time, scientists have used brain imaging experiments to reveal how the drug, also known as MDMA, produces feelings of euphoria.
Although it has been recognised as a popular recreational drug since the 1980s there has been little research into how it affects the brain and its medical potential.
Researchers at Imperial College London used 25 volunteers who underwent brain scans on two occasions – once after taking the drug and once after taking a placebo.
Robin Carhart-Harris, from the Department of Medicine at Imperial, said: "We found that MDMA caused reduced blood flow in regions of the brain linked to emotion and memory. These effects may be related to the feelings of euphoria that people experience on the drug."
Volunteers were asked to recall their favourite and worst memories while inside a scanner. Happy memories were more emotionally intense in the participants who took ecstasy than those who had not. Bad memories were also reported less negatively.
Carhart-Harris said: "In healthy volunteers, MDMA seems to lessen the impact of painful memories. This fits with the idea that it could help patients with PTSD revisit their traumatic experiences in psychotherapy without being overwhelmed by negative emotions, but we need to do studies in PTSD patients to see if the drug affects them in the same way."
Findings showed the drug decreases activity in the limbic system, an area of the brain involved in emotional responses. Communication between the medial temporal lobe and the medial prefrontal cortex – which are involved in emotional control – were reduced.
These effects are opposite to the patterns seen in patients suffering from anxiety disorders.
Ecstacy also increased communication between the amygdala and the hippocampus. In PTSD patients, this is reversed, suggesting the drug could be used to treat the illness.
Previously, ecstasy has been investigated as a complimentary therapy in the treatment of PTSD, with a pilot study from the US showing positive preliminary results.
David Nutt, who led the study, said: "The findings suggest possible clinical uses of MDMA in treating anxiety and PTSD, but we need to be careful about drawing too many conclusions from a study in healthy volunteers. We would have to do studies in patients to see if we find the same effects."