BTW the article is a little US-centric; in the UK it's usually called Mandy or MD ("emdee") rather than Molly.
It was used in a therapy-like way for all those (underground) years, not strictly for dancing/clubs/house parties. People had informal couples therapy, or trauma therapy where painful memories surfaced and they could be dealt with in a safe space free of inhibitions. Only now it's more formal and the doctors are involved.
From Wikipedia:
> MDMA was first synthesized in 1912 by Merck chemist Anton Köllisch. At the time, Merck was interested in developing substances that stopped abnormal bleeding.
> Alexander Shulgin reported he synthesized MDMA in 1965 […], but did not test the psychoactivity of the compound at this time.
> Shulgin occasionally used MDMA for relaxation, […] and gave the drug to friends, researchers, and others who he thought could benefit from it.[…]. When [Leo Zeff, a psychotherapist who had been known to use psychedelic substances in his practice] tried the drug in 1977, Zeff was impressed with the effects of MDMA and came out of his semi-retirement to promote its use in therapy.
That said, it seems he first consumed it in Sept '76 and that event put it in psychotherapy circles.