R -MDDMA is a Safer Analogue of MDMA with Therapeutic Potential

Recent clinical evidence suggests that racemic 3,4-methylenedioxymethamphetamine (MDMA) might be useful for treating a range of neuropsychiatric diseases including post-traumatic stress disorder (PTSD) and depression. However, concerns about its abuse potential stemming from its monoamine releasing properties have hampered its clinical development. Thus, safer analogues of racemic MDMA with comparable therapeutic effects are highly desirable. Here, we compare the pharmacological effects of MDMA enantiomers with those of its methylated analogue 3,4-methylenedioxy- N, N -dimethylamphetamine (MDDMA). We found that R -MDDMA did not directly activate 5-HT2B receptors, induce serotonin efflux, produce a head-twitch response, impact body temperature, or induce hyperlocomotion at therapeutically relevant doses. However, it still promoted structural neuroplasticity in cortical neurons, facilitated fear extinction learning, and produced sustained antidepressant-like effects. Taken together, our results suggest that R -MDDMA might be a safer MDMA analogue with similar therapeutic properties.