Grange Hill's kids asked Britain to "Just Say No" to drugs more than 25 years ago, but it seems their plea fell on deaf ears. One in three adults in England and Wales have used illicit drugs in their lifetime, according to the latest British Crime Survey, with almost 3 million adults breaking the law to pop a pill, roll a joint, inject heroin or snort a line of cocaine, among other narcotics, in the past year alone.

But long before Zammo Maguire brought the issue of addiction to mainstream children's TV, drug use in the UK was well under way. As Harry Shapiro, rock journalist and author of Waiting for the Man: The Story of Drugs and Popular Music, says, there have always been "tipping points for drugs down the decades": in the 1950s, when there were only a reported 317 addicts to "manufactured" drugs in Britain, the idea of the alcoholic was born; a decade on, the counterculture's cherished LSD was perceived as such a threat that, in 1966, two national newspapers urged the government to outlaw it.

By 1979, cannabis use had peaked; the "heroin epidemic" hit Britain's cities in the 1980s and the Trainspotting generation was born; the rave scene and designer drugs of the 1990s followed and the Home Office estimated that 1.5 million Ecstasy tablets were being popped every weekend in 1995, the same year Leah Betts died four hours after taking the drug, and her haunting image made front-page news. By the noughties, the UK was branded "Europe's cocaine capital" by the UN, with the number of users rising by 25 per cent between 2008 and 2009, peaking at 1 million. k

The addiction psychiatrist and founder of the Global Drug Survey, Adam Winstock, has defined the current decade as one of "unparalleled choice", and while cocaine, Ecstasy and cannabis remain Britain's most popular drugs, new "legal highs" and other synthetic drugs are appearing on the market at the rate of one a week, warns the EU's drug agency, which says 10 per cent of Brits have tried them.

The Home Affairs Committee is currently exploring government policy and sanctions regarding drugs, and earlier this year heard the comedian, actor and renowned former user Russell Brand tell them that there remains a "wilful ignorance" about just what fuels Britain's addiction. Admitting that his life had been blighted by excess, Brand added that drug addiction was primarily "an illness".

Do others agree? We asked those who have been affected by each decade's drug of choice since the 1950s. Some credit them with opening up their world; others nearly had their lives destroyed; while the rest took them for fun. But what they all agree is that if Grange Hill's motto is falling on deaf ears, Britain needs to find new ways of broaching the conversation.

1950s Alcohol

James McPherson, 76, from Glasgow, had his first drink in 1952. Six decades later and after suffering blackouts, broken bones and hallucinations as a result of his alcoholism, he says he thinks he has his relationship with the substance under control.

"I had my first drink at 17; it's what everyone did. As far as Glasgow was concerned, all the fathers seemed to drink at the weekend. There didn't seem to be many drugs in Glasgow then – I never saw anyone with hash. Maybe in London, but not where I was.

"Pubs used to shut at about 9.30pm, so people would throw down a couple of whiskeys at the last minute. It's a wee bit different now, I don't see that many drunken people – nobody can afford to drink seven days a week and the pubs are open all day.

"I would binge a bit, but I was in the Merchant Navy then, so I couldn't drink too much. Then, at around 23, I got married and started out as a bus driver and then a lorry driver, which I did for 25 years. At night I used to buy a bottle of whiskey on the way home. I would sit across the road from my house and swallow about a quarter. I didn't know what kind of mood my wife would be in and it calmed me down. Then it went to half-bottles, and then to one bottle a day.

"It didn't interfere with my work; I always turned up. But then 10 years ago or so, it started to become more of a problem. I think that anybody who drinks a bottle a day is an alcoholic – I used to spend up to £80 a week on whiskey. Then I started having blackouts after drinking. They started before I knew it was happening – I got cracked ribs, and a broken pelvis and collarbone at different times. They didn't last for long, about 10 seconds, but they were frightening. Then I started getting the DTs [delirium tremens] and seeing things such as beetles on the ceiling when I was in bed.

"Now, I have check-ups at my house, but I've cut down on my drinking – I bought a bottle of whiskey last week and only just finished it. It's just a habit now. It's funny how the best things in the world, drinking and smoking, bring you more trouble than anything else."

1960s LSD

Gregory Sams, 63, from north London, is an author, yet is best-known for inventing the vegeburger. He credits LSD with opening up his interest in organic foods – he co-founded Whole Earth Foods with his brother.

"On my very first acid trip in Berkeley, California, in 1966, I climbed to the top of Strawberry Canyon, overlooking San Francisco Bay. I stared into the sun for 20 minutes and had a perception of it as a life form, as a conscious being. I was 17 then, but my recent book, Sun of God, now explores this theme. LSD has been one of the most valuable guides in my life. It helped make me aware of who I was and what I needed to do.

"I took it half-a-dozen times when I was in America and then took it some more when I was back in England, during the Summer of Love. It was the fundamental engine of the 1960s. At that point, it was a closed, regimented and black-and-white culture. Perhaps now our culture has blossomed there is not so much need for LSD, but at the time it kick-started the inner awareness that led people into areas such as natural healing, yoga and meditation.

"For me, it was about food. Insights from LSD helped me recognise the importance of what we eat. [My brother] Craig and I started the first organic, natural food company, Harmony Foods. Our macrobiotic restaurant Seed, near Paddington, was the only restaurant serving the countercultural scene of the 1960s. It wasn't just us; various people around the planet at that time manifested new 'green' additions to the culture as a result of their expanded vision.

"LSD has been demonised to a high degree, but rarely by those who took it. I am aware of a few people who 'lost it' on an acid trip and never fully came back; perhaps they triggered a pre-existing condition. That is sad, but compared with alcohol, speed, heroin or Valium, I think there have been minimal negative effects.

"I rediscovered acid in the 1990s and occasionally revisit. I have had three difficult trips in my life that I'd rather not have had, but they did no damage. I believe our cultural evolution has been sadly diminished by prohibition of the psychedelic experience."

1970s cannabis

Peter Reynolds, 54, from Dorset, is a writer and party leader of Clear, the political group calling for cannabis law reform in Britain. He has been smoking cannabis since he was 14 years old and now smokes daily. While he says cannabis culture has changed over the past four decades, he believes it is still misunderstood.

"It was 1971, and I was 14 and on my way home from school when I was first introduced to cannabis. I met my friend and he said, 'I've got it.' We went back to his bedroom and rolled a joint on an LP. It was probably Bob Dylan or the Rolling Stones. I remember being violently sick.

"When I finished my O-levels, eight friends and I went to Amsterdam. I was supposed to come back and do my A-levels, but instead I stayed there for two years. At 18, I decided I'd better grow up and get a job. I found my way into advertising sales and very quickly became a copywriter. Certainly within the advertising business, cannabis use was rife. Everybody was using it. Not just as a relaxant, but as a way of helping creativity. We would go off to a hotel with a brief from a client. We would sit around rolling joints, coming up with great ideas.

"It was very much a product of the time – for a lot of young people, it was the forbidden fruit. Now, it has become much more mainstream. I would only smoke then once or twice a week. I don't think it hindered my career.

"Some people do abuse it and if you start smoking at 14, any psychoactive substance has the potential for harm – your brain is still developing. But I think life is full of risks. From an early age, I was outraged at the law saying I couldn't use it. I saw it an infringement of my personal liberty.

"The best solution, in my opinion, is to regulate it. Then you can control it. The only ID a dealer needs to see now is a £20 note. If you had to go to a shop [to buy it], you would no doubt need to prove how old you were. If you had difficulties, you could get advice about it. Prohibition is not control at all. It's just shoving it under the carpet and trying to ignore it; a foolhardy idea."

1980s heroin

Erin, 42, is founder and editor of "Black Poppy", a national magazine by and for people who use drugs. She lives in London, and is one of an estimated 400 people in England who are prescribed heroin on the NHS.

"It was 1985, I was 15, and there was a little crew of us in Australia discovering drugs. I saw pictures of androgynous youths with fags hanging out of their mouths, looking scruffy but satisfied – like they knew something I didn't. I found that really intriguing, as though they had stuck two fingers up at society. My plan was to experiment with life for a couple of years and then buckle down and go to university and get a job.

"I wasn't that keen on heroin initially; it wasn't until an opportunity came up to deal some that I developed a habit. By the time I came to the UK, in 1989, my mum thought k I was going to die. The woolly image of the slightly vulnerable but untouchable heroin addict was an illusion: in reality you're feared and distrusted.

"I got into prostitution; I thought work gave me a bit of control; it allowed me to pay for heroin when I wanted it. You need three or four hits a day, a little bit more if you can get it. It was 1995 when I was diagnosed with HIV. I hadn't met anyone with it in Australia but Europe was in the middle of an HIV epidemic.

"I tried everything to get off it. About seven years in, I sought treatment. I found there was no treatment equality, only unenlightened, punitive treatment regimes. After about 10 years of trying the 'one-size-fits-all' treatment approach, I went to see a private doctor. He was the first to ask me what it was I thought I needed.

"It was a revelation – I knew what I needed and it was heroin on prescription. I have a new doctor with whom I share a dignified and trusting relationship. I see her every fortnight and pick up pharmaceutically prepared diamorphine (heroin) from my local chemist, and for the first time I can really contribute and participate fully in life. Once you take heroin out of the black market, everything changes – the anxiety and fear dissipate.

"I know now I'll come off this prescription – I don't want to be dependent for years to come, but we must have these options today."

1990s ecstasy

Mark Donne, 36, is a freelance film-maker from east London. He grew up in Margate, Kent, and was introduced to Ecstasy through the rave scene. While some of his friends became addicted to narcotics and ended up in prison, he ended his relationship with illicit drugs two-and-a-half years ago when he became a father for the first time.

"Drugs were ubiquitous in Margate in the 1990s, as in other coastal towns in Britain. We were the fourth-biggest unemployment black spot in Europe, there were fraught social problems, but paradoxically, there were stricter regulations in pubs than at raves. The first time I experienced Ecstasy, I paid £15 a tablet; now it's as cheap as acid.

"Drinking and smoking were hardwired into family life – mine and my friends' parents were always in the pub – but there was a mythology around the drug that went hand-in-hand with the new music. My first time on Ecstasy was also the first time I encountered any type of dance music – I had the natural rhythm of a lamppost.

"Overnight, little shops became record stores, with decks. Soon, you didn't want to be sitting in the park drinking a cider, you wanted to be with the crowd. I would mainly take Ecstasy at weekends; it became a very regular thing. Any kind of anxiety we might have had that it was illegal just evaporated. Everyone was testing these things out.

"I remember Leah Betts's death. It sent shockwaves through my peer group – but they diminished before long and it didn't stop me taking the drug. My memory of my years taking Ecstasy is fond, but by 21, I got quite bored with the scene – I was never terribly into dance music.

"Most people I grew up with had an extremely problematic relationship with drugs. It's clichéd to say that you go from Ecstasy to cocaine and heroin and crack, but three out of seven in my group of friends became heroin addicts and went to prison.

"When I had my daughter, I thought it was a decent time to guillotine my relationship with drugs. If my daughter told me she was thinking about trying drugs, I'd urge her to do so in the most responsible way. In society, we're so far away from having a grown-up discourse about drugs."

2000s cocaine

Sarah Graham, 43, from Surrey, sits on the Government's Advisory Council on Misuse of Drugs and is director of her own addiction and holistic health company. The former TV director is also a recovering cocaine user, who says her addiction got so bad at the start of the Millennium that it almost killed her.

"The first line of cocaine I did changed everything. It took away all the nagging insecurity, or low self-worth. I was at the Groucho Club, having just started a job at the BBC, when somebody asked me if I wanted to go to the toilet for a line. I felt like it might help me feel a part of that world.

"It was seen as exclusive – a Gucci-like drug. From the word go, I didn't want the feeling to stop. That first night, I ended up knocking on the door of the person who gave it to me, asking for more. For a long time, I just binged on the weekends, taking anything from one gram to three a night.

"When I went freelance, I was spending at least half of what I earnt on cocaine and alcohol – £600 a week. I always thought if I turned up to work and did my job, I didn't have a problem.

"I hit a physical wall when I was working on The Big Breakfast. I used cocaine to fuel my work addiction and would skip sleep and food. I had to take two weeks off – it was then I knew something had to change.

"I had struggled to stay sober all summer, and then my dad died in November 2001. I got through his funeral, but the night after, I called my dealer. I descended into hell and was snorting a line every minute for 24 hours. By December, I ended up in treatment. I felt like all the colour had been sucked out of my life; I was an absolute suicidal mess. It was the final thing – it blew apart all my denial.

"I spent seven-and-a-half months at the Priory. Treatment cost me in excess of £25,000 and I had to sell my house. But it exposed me to really good therapy and helped me understand the cost attached to addiction. Lots of people who'd never dream of taking heroin, another Class-A substance, take cocaine. I now know that every time I took it was like playing Russian roulette.

"I have been given the gift of recovery and want to support other people and help them understand the trauma behind addiction."

2010s legal highs

Jay (not her real name), 25, is a freelance writer from Nottingham. She has been taking drugs recreationally for more than a decade, but in the past year has experimented with so-called "legal highs" and other synthetic drugs. She has taken Mephedrone, known as MCAT or Meow Meow, which was banned in 2010, as well as synthetic drugs 2C-I and 2C-B, whose effects are akin to LSD and Ecstasy.

"Legal highs were big on the Nottingham scene last year – there were new ones coming out all the time. It's actually insane, they tweak one chemical compound and, boom, it's legal. I don't particularly like them and I try to stay away from them now. People lose themselves on them and you don't know the long-term effect on your mental health.

"MCAT is kind of like a mixture of cocaine and Ecstasy – you feel really loved-up for about half-an-hour. I could take a gram or two in a single night, but I knew people who would take bags of the stuff – up to four grams a night, for three or four days continuously. It's moreish.

"Then MCAT stopped being so available, but there was 2C-I or 2C-B, which you can eat or snort. The high lasts about an hour-and-a-half and you get visuals like you do on acid. But the day after, I felt awful. Three days later, I wasn't very pleasant to be around. I was in such a foul mood, and some people I knew became absolute monsters.

"I started out taking stuff at 13, and back then, things seemed to be a lot better-quality, cleaner. Now, a lot of people are trying to make money and overcome legal obstacles, and because of that we're getting a lot of crap. Whether it's legal doesn't hold any scope with me – it's about how it makes me feel in the long term. MCAT seems to be the one that really gripped people, but a few of us got really concerned. Some people completely lost control of their emotions."