Yes, MDMA has been shown to be an effective complement to exposure therapy. As I understand, with mdma, the goal is to develop a new emotional association linki

Yes, MDMA has been shown to be an effective complement to exposure therapy. As I understand, with mdma, the goal is to develop a new emotional association linking the experience to the intense euphoria the MDMA induces. As you point out in another comment, MDMA actually increases norepinephrine levels, which I suppose would enhance the strength of the new associations. As for neurotoxicity, limiting use to less than once a month is quite effective at reducing it, I've heard. This is probably not much of a problem for theraputic use, but if it needs to be administered more frequently, there's some evidence that taking an SSRI before taking MDMA will reduce toxicity (don't do this, you might risk seratonin syndrome). DXM too has been shown effective at reducing amphetamine toxicity, so it might also help (also don't do this). If MDMA is ever rescheduled to allow for research, though, these techniques might allow more frequent use in theraputic settings.