While out on the weekend, reading a paper on drugs and memory yesterday and having previously talked with with people about inducing drug states without drugs I had this idea.

Would it be possible to use cognitive enhancers, specifically memory and emotional memory enhancers to create more connectivity/plasticity between areas which are activated while under the influence of mdma (as an example)? And then train these drug induced states in somebody, with this more efficient memory, so they could experience the state without the chemical?

Knowing people who have tried this or something similar, without long-term success, I'd have to say that I don't think it can be done. Any learning is very likely to be short-term, on the order of weeks at best.