A single would also look forward to finding at least an innate (i.e. not induced specifically via the drug but e.g. from the anticipation to it) dopamine response to opioid administration in opioid addicts. Alas, although a single is found in animal models (and it's less than for psychostimulants), in https://mephedronmephedronkaufen01223.buscawiki.com/2103528/rumored_buzz_on_methylon