There was a time, while the dance music was pumping and before free raves were closed down, when it seemed as if one young generation had finally found the perfect pill. It got them high, it was cheap, it did not send them to hell and back on bad trips and it was not addictive. They had found ecstasy.
Hundreds of thousands of kids were dropping Es, dancing all night without so much as a mouthful of expensive alcohol and heading for school or work on Monday morning pretty much intact. They still are.
Ecstasy is the way of the weekend for large numbers of young people. The latest figures in Britain show that 12 per cent of 16- to 24-year-olds have taken it at some time. Only 2 per cent effectively admit to regular use, but not everybody is going to confess to the crime survey; there's no doubt the real figures are higher. Look at the temptation: a pill that will give you euphoria and energy all night long for under a tenner.
But it's starting to look as though it's all going sour. One study after another is suggesting ecstasy can cause brain damage. No, it isn't likely to leave you a vegetable in the near future, but evidence seems to be steadily accumulating that it is doing something to your brain, and it may be irreversible.
The research is still in its early stages, there's still time for most of it to be overturned, but it's all pointing the same way. The latest study in Britain is a pilot, involving 30 people aged 18-25 who took psychological tests to establish whether ecstasy had affected their working memory - the part that enables us to carry out routine everyday tasks such as cooking a meal. It also tested their ability to take in and use information.
The scientists, from Edge Hill college of higher education in Ormskirk, Lancashire, found that ecstasy users performed significantly worse than the others. "We don't want to start any scares or panics," says Dr Philip Murphy, one of the authors of the study published in the British Journal of Psychology. "It's a pilot study with a relatively small sample. We have to balance that with our responsibility as scientists to point out potential dangers that we discover.
"The problems that we found in working memory emerged when people worked under pressure and, most notably, under time pressure. For normal working circumstances there was no problem." So could ecstasy cause problems for people in high-pressure jobs, late in their lives? "That is perfectly conceivable," he says.
In December came the really scary news, published in the highly reputable Lancet medical journal, that a group of scientists in the US had scanned human brains and found damage to serotonin neurons caused, they believe, by ecstasy. Serotonin is the chemical in the brain partly responsible for mood changes; neuroscientists are beginning to believe people who drop Es may be at greater risk of mood and sleep disturbance, aggressive tendencies and anxiety.
All drugs cause mood swings. If you go high, you must come down low. But the most alarming part of the research is the suggestion that some of the changes caused in the brain could be permanent. Prof Una McCann of the US National Institute of Mental Health in Bethesda, Maryland, described a series of experiments on monkeys carried out in laboratories around the globe. Each was given a four-day course of ecstasy. Every single animal showed signs of brain damage seven years later.
These are early days. Monkeys are not humans. Much more research needs to be done. The scientists cannot be sure how much ecstasy their human volunteers have taken and what other drugs they may have mixed it with. So it is too early to say whether we are heading for a generation of the neurologically impaired - and some think that there is a danger of making the wrong risk assessment.
Children are already confused because of the spin that has been put on information about ecstasy, say some campaigners. After the huge publicity given to the death of British teenager Leah Betts after she took ecstasy, and the campaign against the drug launched by her father, research showed that schoolchildren thought ecstasy was more dangerous than cocaine and heroin.
Yet among healthy young people there have been only about 80 recorded deaths while taking ecstasy, and nearly all collapsed with severe heat-stroke at raves. "A lot depends on what sort of criteria you are using to measure risk," says Harry Shapiro of the drugs information charity Drugscope.
"If you are talking about addiction, drugs like heroin, cocaine, tobacco and alcohol are going to come fairly high up the list, but you don't drop dead from smoking a packet of cigarettes. There have been a number of people who have died after taking one pill. It's the same as with glue-sniffing. It could be the first time."
E-users may be moved by the threat of brain damage - but they may not. Young people's risk perception is different from that of older people. "Everyone thinks they are immortal," says Shapiro. Faced with the possibility of something happening to them 20 to 30 years down the line they may decide, as they frequently do with cigarettes, to say: "I'm not going to bother with that."
John McKevitt, a graphic designer, has no intention of worrying about scare stories, and he is a relatively long-term user of the drug. "You feel absolutely brilliant," he says. "That first rush is fantastic. Plus it's incredibly social and it's good to dance to - all the stuff you normally hear about it. I am 31 now and I started taking E when I was 21, though only using it heavily - around once a week - for about a year of that. The rest of the time might be once a month or so. But when I say using it, that would be two pills, or occasionally three.
"I've never had any negative side-effects or negative experiences, and I have never seen anyone have a negative experience. I have got a bit bored with the dance scene, so now when I take it it would be round with some friends. But I have good friends who still use it regularly at raves.
"I have never been one for the scare stories. I do think there should be more testing on it, but it wouldn't put me off taking it."
There are others who worry more. "When I was at university I used to take ecstasy quite a lot," says Anna Thornton (25), an administrator. "I was really into the club scene and I knew lots of people who went mad on it. I did really enjoy it and then I managed to stop in the last year. I do feel now that it's made me a bit paranoid and panicky. It's hard to tell, but discussing it with my friends who have been through similar times, they feel the same way as well.
"One of my friends definitely thinks that it's made her have panic attacks and is convinced it has had a really bad effect on her. I think it does affect your memory. I don't know whether it's a paranoia of mine that I have a bad memory, but I do feel it's slowed me down in that way."
While everybody agrees ecstasy is not physically addictive, Dr Murphy is one of those who thinks it may cause psychological dependence - in that anything that makes you feel good makes you want it again and again. Scott Ferguson, a 23-year-old student, says the highs are so good that the lows, to him, feel really bad.
"I haven't taken any for a year or so. I must have taken E for the first time when I was 17. All my mates were doing it. It was amazing - a real rush, like nothing I had ever done before. I had done acid and smoked cannabis, but it was like nothing else, a total, euphoric feeling. I have taken it a few times, about a year ago, but now I don't want to get that spaced out, because the come-downs are a nightmare.
"The come-downs get worse over time. It's like drinking: as you get older the hangovers get worse. I think your body gets a bit weak. The next day you are feeling completely washed out. The highs are really happy and loved up and everything's great, and the lows are the complete opposite of that. I hope I haven't suffered any long-term effects but I imagine that heavy use would affect you. It's mental damage, isn't it?"
Ecstasy - formally known as MDMA - was first synthesised in 1912. It is part of a group of drugs known as MDA, some of which (including MDMA) are derived from the oils of natural products such as nutmeg and sassafras.
But from a very early stage, ecstasy was considered benign. It was used by marital therapists in the US because it diffused the hostility of angry couples, allowing them to talk civilly to each other. It has only been available in Ireland and the UK since the mid-1980s, most of it initially produced in underground labs in Holland and Belgium.
In March, the British Police Foundation made a pragmatic risk assessment, saying that ecstasy should not be bracketed with heroin and cocaine, which kill and destroy lives. "Although deaths from ecstasy are highly publicised, it probably kills fewer than 10 people each year which, though deeply distressing for the surviving relatives and friends, is a small percentage of the many thousands of people who use it each week," said its report.
Nor is it clear what killed those victims. Was it E and the cocktail of drugs in a pill, or hyperthermia, dehydration, or excessive rehydration because of acute thirst (the verdict at the inquiry into Leah Betts's death).
The foundation recommended that the definition of ecstasy be moved from class A to class B - not least so that those who drop Es will not be emboldened to try heroin, which is currently in the same class.
If there is such a thing as a fashion in drugs, then E could be on the way out. Harsh publicity about its dangers may well persuade some young people not to take it. The trouble is, say campaigners, they may look elsewhere for a high. And there are some drugs that do not go out of fashion - because those who use them become terminally addicted to them.
Names of ecstasy users have been changed.