But in the 1980s MDMA, which at the time was still unregulated, escaped its semi-underground psychotherapeutic milieu and began to be taken by young people for the sheer fun of it. In a panic, America's Drug Enforcement Agency (DEA), unaware of the therapeutic MDMA network, made an emergency classification in 1985 that placed MDMA in Schedule I-the most restrictive category for drugs with "a high potential for abuse" and "no currently accepted medical use".

Schedule I also includes marijuana, LSD, psilocybin, mescaline and heroin (though rules vary widely: heroin, for example, is available by prescription in Britain and some other countries). Cocaine, amphetamines, opium, morphine and others are in Schedule II and can be prescribed by doctors under DEA supervision. Although 500,000 doses of MDMA had by this point been used in therapeutic settings, the compound was thereafter banned worldwide.

Some therapists went underground, continuing MDMA treatment illegally, using illicit supplies. "It's a very simple compound to make," remarks Mr Shulgin.

Ironically, once it became illegal, MDMA's recreational use exploded. The UN estimates that at least 9m people-compared with 12m heroin and 16m cocaine users-consume round about 100 tonnes of MDMA and related compounds worldwide each year. The criminal nature of the business makes it difficult to assess the dosage or purity of the MDMA being consumed and it can have lethal effects. But millions of people, rolling about on fake fur pillows or waving glowsticks to electronic music, attest to feeling good. "The first time I ever did it was literally the first time in my life that I felt good in my body," says Ms Westerfield, who took MDMA recreationally in the 1980s (half the study participants had swallowed the drug occasionally in the past).

... contd.