"There's been a big rise in the number of cannabis users being admitted to hospital with mental health problems." "The drug GHB, which has been used by sex attackers to sedate their victims, is to be banned by the government." "From amphetamines to alcohol..." "This is called crystal meth, ice and Nazi crank." "The drug methyl amphetamine... ..cannabis to crystal meth..." "LSD is far worse even than...heroin." "..ethanol to ecstasy..." "I swear to God, this will take over anything you love, cos you love that more - he is master." "Drugs, legal and illegal, have never been so easily available." "They provoke in the media a sustained, intense and for the most part science-free feeding frenzy." "The dangers of taking ecstasy are again in the spotlight." "Last year, the number of deaths caused by the drug more than doubled in England and Wales." "In this film, we examine the latest scientific evidence behind 20 of the country's most widely abused substances." "And ask what is Britain's most dangerous drug?" "Well, a lot of it's mixing, isn't it, corruption by dealers." "How it effects you physically." "Dependency." "Yes, side effects, long-term effects, financial effects." "It can also cause mental instability." "All of them are dangerous." "The illegality of drugs makes them dangerous." "In the last two years, a group of British scientists and experts have been re-evaluating 20 of the country's most harmful drugs." "If alcohol was invented today, it would be illegal." "There's no question." "The debate still goes on as to whether or not cannabis can cause schizophrenia." "It can certainly cause an acute psychosis." "If you look at ecstasy, it isn't a drug that causes significant problems." "Yet, if you ask the public, they would probably rate ecstasy as something that was very dangerous." "The group, led by Professor David Nutt, had a simple aim - to create the first scientifically valid list of drugs ranked in order of harm." "They used three criteria." "One is what the drug does to the person who takes it." "If it stops you breathing, that's a serious problem." "And then there's the issue of how addictive drugs are." "An addictive drug tends to lead people to use more of it because they can't break the habit." "And then the third aspect of drug use, the third harm, group of harms, comes from the consequences to society." "As they applied these criteria to each of the 20 drugs, it soon became clear how contentious this approach would be." "Conventional wisdom was left behind and replaced with a radical reassessment of what actually defines the dangers of a drug." "The resulting list is surprising, controversial and certain to be challenged but, most importantly, it's based not on myth but science." "At number 20, the least dangerous drug on the list is a green-leafed shrub called Khat." "This legal stimulant drug makes the user feel alert and energised, but used in excess it can lead to insomnia, impotence and high blood pressure." "Popular among the Somalian community, there are estimated to be 40,000 users in the UK." "It can be harmful, particularly if it's contaminated with pesticides, we think it may cause some people hepatitis." "There have been cases of individuals becoming psychotic from using large amounts." "There have been no recorded deaths from its use." "It's not particularly addictive, it's not particularly harmful." "At number 19 is another legal drug, alkyl nitrate, better known as poppers." "Sniffed straight from the bottle, it delivers a short sharp high and relaxes sphincter muscles." "Visibly on sale tonight in London's West End, poppers or amyl nitrate." "The effect is brief but can leave the user feeling sick and weak and is toxic if swallowed." "It's non-addictive and used by over 400,000 people in the UK." "Both Khat and poppers are legal and neither are particularly contentious but the substance next on the list turns out to be one of the most controversial Class A drugs in Britain." "In the 15 years I've worked as a GP," "I've never seen a patient presenting with a problem with ecstasy." "18 places away from the top of the list, one of the country's most infamous drugs..." "Ecstasy." "With over half a million users in just England and Wales, and a recorded average of 27 deaths a year, this ranking massively conflicts with its reputation." "There's always been risks involved with ecstasy." "We've never quite known what all those risks are." "There has always been dangers of brain damage." "It's not been confirmed." "In the early days we didn't understand why it caused death, and then we realised it was due to people dehydrating" "First synthesised in 1912, ecstasy was originally patented to control bleeding from wounds." "But in the 1970s, it was introduced illegally into the dance scene." "Most people who take it once take it again." "It can introduce you to dancing, to a different way of being, to sharing a communal spirit, blokes hugging blokes, things being nice and simple, but it can also do your head in." "So what do we know about ecstasy?" "We know that it's a stimulant drug that can bring on mild hallucinations." "It produces feelings of euphoria, empathy and energy and causes increases in body temperature and heart rate and when you digest an ecstasy pill it causes the release of the chemical messenger serotonin within the brain, which is responsible for regulating mood and memory." "So I can tell you what drugs do now but what we don't yet understand is how interacting with those molecules in the brain leads to long-term changes in brain function." "There's a lot of work to be done to understand how the brain adapts and whether that leads to long-term problems." "Professor Val Curran has been studying the effects of ecstasy on the brain for the past ten years." "The headlines at one point were very much that ecstasy could cause brain damage." "Within the past year, the first research has been published indicating that chronic use of ecstasy could impair memory." "And that brain damage could be permanent." "They say the damage appears to be irreversible." "And a lot of that was based on research with rats and with monkeys." "It was difficult to generalise from animals to humans because of the very different dosages, the way it was administered and the patterns of use over time." "So why is it that it's only number 18 on this list of dangerous drugs?" "Some long-term users of ecstasy have experienced disruptions in memory and their normal attention to information, so it's not a drug that's hazard-free by any means." "But having said that, many thousands of people in the UK have tried it and a good proportion of those people derived pleasure and good experience from it so I'm not going to say that it's a very dangerous drug." "Professor Curran has carried out some of the only experiments in this country where ecstasy is actually given to human volunteers in order to study its effects on the brain." "We gave ecstasy, an 80 milligram dose, so quite a low dose, to healthy people who had only taken the drug a few times and we studied the effects in a laboratory, then recorded a whole range of cognitive tests including memory." "We did find one problem which was a deficit two hours after they'd taken the drug in terms of memory, so they were impaired." "But six hours later they were back to normal." "What our studies have shown is that when people have given up ecstasy for at least a year their brains seem to go entirely back to normal." "They don't differ from people who've used other kinds of drugs and not ecstasy." "So it looks like at the moment that the effects are reversible." "I mean there is always a need for future research because there might be a way in which, as the brain ages, effects might come through, but they're certainly not as big as initial research suggested." "Even if other studies have shown differing opinions on the dangers of ecstasy, this group of experts weighing up all the available evidence had little doubt that ecstasy deserved to be no higher than number 18." "All drugs are harmful to a certain extent, even aspirin, but in terms of the risk to the individual and the risks to society, it is nowhere near the league of the other drugs on the list." "Our classification showed ecstasy was certainly well below most of the other Class A drugs and it does seem to be in the wrong class being Class A." "The origins of the British system of labelling drugs Classes A, B or C came about in 1971 after the explosion of recreational drug use in the 1960s." "As a scientific framework for assigning the relative weights to dangerousness of drugs in the UK, it doesn't have a lot going for it." "And experts from many countries are working together to assess the dangers of this new social problem." "And it's this 35-year-old Misuse of Drugs Act that still defines the British attitude to drugs today." "Things were put there owing to very often just prejudice or ignorance or..." "Any way, knowledge has advanced in the last 30 years and they've got stuck there." "Nowhere is this discrepancy more apparent than in the move from the Class A drug ecstasy at number 18 to a Class C drug in 17th place." "GHB or Gamma-Hydroxybutyric acid." "More than 5,000 British women say they've been the victim of drug-induced date rape." "As a sedative, a small amount of GHB makes you happy, sensual and uninhibited." "There have been concerns about it being used in date rape." "In fact, the evidence is quite low and very few cases of date rape probably involve GHB." "You can smell it." "It's not a particularly easy drug to hide." "But its dangers are rated higher than those of ecstasy because the difference between a dose of GHB that gives a pleasant buzz and one that can kill you is barely noticeable." "And when mixed with alcohol it can be fatal." "The amount used in this country is unknown but numbers are very low of three recorded deaths a year." "In 16th place, another Class C drug, the popular muscle-enhancing anabolic steroids." "Abuse of these drugs, can cause enormous amounts of damage to the individual." "From becoming sterile to high risk of liver failure and even strokes or heart attacks." "There are over 42,000 users in just England and Wales and the misuse of these drugs can bring on aggression and violence." "At number 15, we find a Class B drug, methylphenidate." "The active ingredient in drugs such as Ritalin, it is an effective treatment for ADHD sufferers and used by around 40,000 prescription users." "These children are being given psychiatric drugs to control their bad behaviour." "When used illegally, the tablets are crushed and snorted for a quick high." "It's a powerful stimulant, so if abused can lead to vomiting, convulsions, tremors and delirium, as well as dependency." "One in 12 of us will spend some part of our lives in a place such as this." "The next drug on the list was also a prescription drug, initially developed as a circulatory and respiratory stimulant in the 1930s and then, during a 15-year period beginning in the '50s, it was prescribed as a psychiatric treatment to over 40,000 patients worldwide." "More than half of them are suffering from a strange mental disease called schizophrenia." "At number 14 is lysergic acid diethylamide, LSD." "It is used by over 83,000 people in the UK yet there have been no recently recorded deaths from its use." "Dr Ronnie Sandison was one of the first people in the UK to use it in psychotherapy over 50 years ago." "LSD really has three effects on people." "It has a general enhancement of what's going on inside." "It's all to do with them, it's all to do with round, with shape." "Everything's coloured, everything, you know, is..." "Oh, it must be to do with orange, not only with orange, but, oh..." "It has some specific effect in raising forgotten memories, particularly traumatic memories." "And thirdly, it seems to allow people the facility to explore those." "LSD did make an important contribution to what you might call science of psychotherapy." "I can do everything." "It fitted in with my idea of what therapy should be." "The drug was administered in a drink of water given at the start of..." "In the 1960s, it was taken up by the Army, who tested it on their troops to see if it could eventually be used in battle to incapacitate the enemy." "25 minutes later, the first effects of the drug became apparent." "The men began to relax and to giggle." "After 35 minutes, one of the radio operators had become incapable of using his set but one hour and ten minutes after taking the drug, with one man climbing a tree to feed the birds, the troop commander gave up," "admitting that he could no longer control himself or his men." "And later that decade, when LSD leaked out into the recreational market, it panicked the establishment and was made an illegal Class A drug." "People who have taken LSD have gone in through plate-glass windows." "We had people who were inside with LSD coming out through plate-glass windows." "Many experts today believe the dangers of LSD are more fiction than fact." "It's physiologically non-toxic." "No-one has ever died from an overdose of LSD." "It's true I think one or two people in the '60s jumped out of windows but that's become a myth which goes on flapping its wings through history." "Dr Ben Sessa is keen to pick up where Ronnie left off and revived the use of LSD in therapy." "If you imagine going along to your typical 50-minute psychotherapy session once a week, one might go for months and months before the defences are broken down and the real crucial material comes out, so the role of LSD is it can speed that process up." "LSD acts firstly on the brain's serotonin system, a part of the brain responsible for feelings of well-being, and subsequently on the pre-frontal cortex, which processes some of our uniquely human abstract thoughts." "It also seems to reduce communication between different brain areas, leading to a loss of inhibitions and an ability to open up, and the complex neurological effects can result in powerful hallucinations." "So we're giving you this LSD, you know, to..." "Today, despite a growing belief of its benefits amongst some parts of the medical community, the laws have made further use in psychotherapy almost impossible." "If you say the words LSD to someone now they think of all the dangers and the adverse effects." "Don't leave me, please!" "We're right to be cautious." "These can be dangerous drugs when used recreationally but I firmly believe that they can be used safely in the context of the clinical environment." "In a sense, I've done my bit and I'm very glad to hand on the mantle as it were to other people and I'm glad that Ben and others of similar calibre are taking it on." "It's very encouraging." "If there is a possibility that LSD or other hallucinogenic drugs can have therapeutic potential in psychiatry then I do believe they should at least be researched to explore this." "Because to leave that stone unturned is potentially closing the door on that group of patients who may benefit." "At number 13, the Class A drug 4MTA, a man-made drug created purely to sell on the street as an alternative to ecstasy." "State government has banned a lethal new designer drug called Flatliner, 33 times more powerful than ecstasy." "Its dangers lie in the fact that even though it is a stimulant, it does not produce the euphoric high that ecstasy does so users take more and more, thinking it hasn't worked, and can eventually overdose." "As a relatively new drug in the UK, the number of users is unknown." "At number 12, a legal drug far more dangerous than we often realise." "From glue to paint to aerosols, the misuse of these drugs is widespread." "The solvents are inhaled so they get into the lungs very quickly." "Many of them are quite toxic chemicals like toluene that have a very toxic effect on the heart." "With over 30,000 users in the UK, we see an average of 50 to 60 deaths a year from solvents, including first-time users." "Somewhere between about five and 20 children a year die either of the heart stopping when they sniff the solvent and others die because they have it in a plastic bag and then they go unconscious and then they inhale the contents." "So from Khat through to solvents, the scientists have placed a variety of drugs from the legal to the very illegal in the bottom half of their chart." "With drugs like acid, E and GHB already covered, at number 11 they reached a crucial turning point with the UK's most commonly used illegal drug, cannabis." "Used by around three million people in the UK, it is responsible for only one recorded death a year." "However, the scientists had no reservations in placing it this high on the list." "Do not underestimate cannabis." "It is not a safe drug just because some people think of it as a herb." "It is not a herb, it is not a drug that can be used with no ill effects." "As cannabis is usually smoked, it hits the brain almost immediately, effecting cannabinoid receptors present everywhere in the brain." "In small doses, it induces euphoria, relaxation and pain relief but in high doses it can bring on paranoia and short-term memory loss." "It can also lead to some form of dependency and it has more recently been linked to lung cancer." "More controversially, some scientists have started to explore the links of long-term use of cannabis and psychosis." "When we look at cannabis and psychosis, what we see is that if you are psychotic, if you've got schizophrenia, smoking cannabis is a bad thing." "Of the hundreds of compounds found in cannabis it seems one of these chemicals, THC or tetrahydrocannabinol, may be linked to psychotic behaviour." "This compound is being used to see if it can recreate similar symptoms in healthy volunteers to those suffered by schizophrenics." "Schizophrenia is a psychiatric illness in which patients will experience a range of bizarre phenomena, things like delusions that some agency is out to get them." "The subjects will be hearing voices of people who aren't actually there." "Dr Garry Honey has been conducting a study in Cambridge where THC is given to the volunteers intravenously over two hours." "Its concentration and purity mean that its effects are not comparable to those of smoking cannabis." "So the THC is getting into the brain very much more quickly than it would if you were smoking cannabis." "That's likely to be a very different experience than the gradual onset of symptoms that you might experience with cannabis." "So this is Tom, one of our volunteers on the study." "We've given him a dose of intravenous THC and these are the first symptoms that he began to experience." "Where I'm looking, I can see in sharp, in intense relief but... the rest of my vision is really closing down and going out of focus, really." "At that point it was sort of almost exciting." "It was, this is fun, this is great, this is a whole new experience." "But it was later on that it started to get a bit, a bit more full-on, really." "When healthy volunteers are exposed to THC, they'll start to experience some of the symptoms that are in some ways similar to the symptoms of schizophrenia." "One hour into the study, the normally extrovert and eloquent Tom starts to have problems expressing himself." "I..." "I'm hesitating to say that I'm, it isn't working very." "It isn't, um," "I think it isn't..." "I can't finish the sentences." "It's bizarre almost watching, seeing myself do this." "It was really difficult to keep communicating it and yet at this point my brain was, was just on fire and I was thinking of all these really interesting things and, "Oh, I must tell them about this because I've just noticed that."" "And yet I couldn't because it was happening far faster than my mouth could keep up." "Do you feel as if there is a conspiracy against you?" "Yes, but not, um, it's not very strong." "I remember thinking, you're asking me whether I'm suspicious but if I'm suspicious, I'm not going to tell you." "What we are trying to answer is, should they become schizophrenic, what type of symptoms might they experience?" "If we can predict those symptoms under drug, the potential is that we could also predict those symptoms during the disease and that would allow us the potential for early intervention strategies." "In these studies, pure THC is given in very high doses and appears to induce similar symptoms to schizophrenia but as yet there is no evidence that the complex combination of ingredients in cannabis can cause psychosis when smoked." "As the controversy linking cannabis and psychosis rumbles on, studies across the globe indicate that the picture is far more complicated than we realise." "An interesting recent study came out of New Zealand and there they showed that smoking cannabis was associated with increased risk of psychotic symptoms but the group that was particularly at risk had a genetic variant of a gene which breaks down dopamine in the brain," "whereas three-quarters of the population don't have that genetic variant." "They seem not to be at risk of getting psychotic symptoms with cannabis." "So it's a complicated area, and genetics as well as cannabis use may play a part." "I love to wake up and have a spliff," "I think it's great." "We'd even smoke in the playground." "The playground, on the benches..." "The study in New Zealand also looked at the age at which people start smoking cannabis and they showed that the earlier start was associated with more likelihood of having these psychotic symptoms." "Would you like some more?" "Yeah." "It's a very hazardous thing to do, to include into the kind of, the diet of a young person, psychoactive drugs." "Their brains are developing, they are by no means mature, perhaps not until the first few years of their twenties." "At number ten, buprenorphine, a Class C opiate normally used for severe pain and as a treatment for heroin dependents." "Buprenorphine is already in use as an injectable pain killer." "When taken orally it can block the effect of heroin." "It is used illegally because of its euphoric and hallucinogenic effects, but without medical guidance it is highly addictive and, being a strong opiate, it can very easily lead to overdose." "The number of illicit users in the UK is unknown." "At number nine, the most deadly drug in the UK." "It kills one fifth of the population and reduces life expectancy on average by ten years." "It causes 40% of all hospital illnesses and it is one of the most addictive drugs available - and yet it remains legal." "In ninth place, the commonly used and still quite popular drug, tobacco." "At around £5 a packet, there are over ten million smokers in the UK and it is responsible for over 114,000 deaths a year." "A lot of people have criticised us for putting tobacco into the Lancet paper." "We did it because we thought it was important that we put in the drug that most people have experience of, and so then they could judge the relative harms and safeties of other drugs in relation to tobacco." "I shall never give up smoking," "I've been smoking too long now and I'm still healthy." "So why should we ban smoking?" "Smoking alone kills more than drugs, alcohol, HIV, suicide, homicide and car crashes combined." "Approximately one of every two life-long smokers will eventually die from smoking." "If current trends continue, five million children alive today in the UK will die prematurely of tobacco-related illnesses." "If you smoke three or four cigarettes you are likely to be addicted for life." "You are unlikely to be able to be what some people call a social smoker." "You are likely to spend the rest of your days trying to give up." "Nicotine is probably the most addictive substance we have currently, amongst all the substances." "In eighth place, amphetamines." "However, when abused, they become incredibly addictive." "As tolerance builds up, so consumption increases, leading to paranoia and depression, with heavy use bringing on panic attacks and violent mood swings." "On the street, they are often cut with other dangerous chemicals." "Benzodiazepines are known to most of us by their pharmaceutical names, like Valium." "They are minor tranquilisers which are used under prescription for treating things like anxiety, insomnia and seizures." "'But after just a few months use, they can cause dependence and side effects." "For years...'" "But illegally abused, they can lead to memory loss, nausea, anxiety and depression." "Consumed with alcohol, they're often fatal and are behind 406 recorded deaths every year in the UK." "At number six, another Class C drug, ketamine." "Normally used as a horse tranquiliser, it has very strong pain-killing effects but has become a popular illegal drug because it is such a strong hallucinogen." "It looks like cocaine, it's snorted like cocaine." "It will give you a wide range of effects, including sort of altering reality, bodily numbness and a dissociation from contact with your surroundings, so that people feel they could stretch their arm up down the end of Tottenham Court Road." "It falls into sixth place on this list because at high doses it can result in heart failure and even stop breathing." "It's particularly dangerous if mixed with any depressant drugs, including alcohol." "Prolonged use can lead to psychological dependence and psychosis." "With only five drugs remaining, the scientists placed a popular legal drug after ketamine." "More harmful than ecstasy, LSD, tobacco, five Class As and 11 illegal drugs, something which kills more people than all of the illegal drugs on this list combined and which is nevertheless used by the majority of the population." "At number five, alcohol." "Around since the earliest days of civilisation, it is used by over two-thirds of the UK population and is implicated in around 40,000 deaths each year." "The problem is that when people think about alcoholism, they think about the chap sitting over there in a doorway with a bottle of cider." "They don't think of the people that go out after work every night and they can't function..." "Before they go home, they need to have those three or four or maybe five drinks." "About the couple that comes home from work and open a bottle of wine." "I never thought I'd end up on a bench drinking in the morning." "Alcohol is probably the biggest problem drug we face today." "I think in terms of the public's health, it's the biggest public health problem we face." "I don't think it's the individual." "I don't think we can blame them." "I think it's the fact that alcohol is so cheap and it's so available and I think as a society we pay lip service to the problems." "We almost laugh at the young person drunk in the street." "We laugh at the hangover that we had from yesterday's drinking." "What do you think is the most dangerous drug?" "Myself, I would say heroin and alcohol." "Alcohol is a sedative and its effects are seen on the brain within five minutes." "It effects several neurotransmitters, including dopamine, which is found in large quantities in the brain's reward pathway." "Stimulation of this system not only causes pleasure but also gives alcohol its addictive qualities." "Alcohol acts as a depressant, but at low doses removes inhibitions so making the person sociable and talkative." "As doses increase, speech begins to slur, it affects co-ordination and brings on nausea and vomiting." "Long-term use can lead to damage of the heart, liver and stomach." "I think if alcohol was introduced today it would certainly have many more sanctions on it than it currently has." "It would probably be classified." "It is the only drug now which we actively encourage people to use, which we under price, which we sell aggressively, and yet we pick up the consequences, we pick up the damage all the time." "There are currently over 180,000 alcohol-related hospital admissions each year." "Deaths have nearly doubled over the past decade." "Around 40% of AE admissions are down to alcohol and the cost to the NHS is up to £1.7 billion a year, and yet we carry on drinking." "'It's becoming the most serious social problem in Britain.'" "We have to make sure that this form of what we often call binge drinking doesn't become a new sort of British disease." "Professor Theodora Duka has been studying a new phenomena in our use of alcohol - the effects of binge drinking." "We started studying binge drinkers and compared them to non-binge drinkers." "Do you see yourselves as binge drinkers?" "Occasionally." "I think I'm a lot more conscious of how much I drink now than I was when I was younger." "What do you think constitutes binge drinking?" "Drinking so much you can't see and you fall over." "Amber and Veronica are involved in a study examining a link between binge drinking and brain damage." "First of all, the volunteers fill in a questionnaire in order to determine their drinking habits." "Once a pattern of traits is established, they move on to computer tasks." "Which are designed to test whether the binge drinkers are different in their cognitive and emotional function." "Binge drinkers will make a mistake and go back to a square that they have visited before." "Binge drinkers have a worse strategy than non-binge drinkers." "And its effects on the brain?" "The type of tasks that appear to be more impaired are tasks which are related to the function of prefrontal cortex - that is more responsible for planning, deciding, following aims." "It is the prefrontal cortex, the area of the brain, that develops so late in life." "The damage being caused comes from the constant stopping-and-starting technique of binge drinking, for example drinking in excess all weekend but not at all during the week." "When you, at one session, drink so much alcohol, then a lot of alcohol which is toxic is absorbed going to the brain and then damages the cells." "Alcohol is then, the next day, slowly eliminated, the brain is challenged to produce a lot of substances which can be toxic and damaging for the brain." "If you had to make the choice, yes, that's what I'm trying to say." "Yes." "Ideally you shouldn't drink too much, whatever you do, because drinking continuously a lot is also bad." "If, in a week, you drink, let's say, two bottles of wine, it is better to drink them day by day during the whole week than two bottles of wine in the weekend." "At number four, the Class A drug, street Methadone." "As an opiate drug, it's similar to heroin, but less addictive." "Methadone is a kind of less-good heroin." "If you ask an opiate addict which they prefer, they'd always go for heroin over methadone but if you haven't got heroin, methadone's not bad." "Prescribed medically, it reduces the withdrawal effects of heroin and tends to lead to a reduction in heroin use." "But used illegally, it is often diluted with other ingredients and strength and necessary dose can be hard to judge." "If it's used to excess by people who aren't tolerant, who haven't been using it, then a very, very small amount of street methadone will kill you." "And because there is no rush like heroin, when you take it, you can overdose easily without ever feeling high." "Used illegally by over 33,000 people in the UK, it causes an average of 295 deaths a year." "In third place, barbiturates, which used to be prescribed for depression, anxiety and insomnia." "When used illicitly, they can make the user feel relaxed, sociable and good humoured." "The problem with the barbiturates, and why they score high on our list, is that if you take an overdose, you are very likely to die." "Chemist robberies are such a regular source of barbiturates and other drugs, some addicts call them canteens." "The small difference between a normal dose and an overdose makes them a highly dangerous drug." "An overdose of barbiturates is like taking an overdose of alcohol." "They both work on the same parts of the brain to stop you breathing." "They are so dangerous that their medical use has dramatically reduced." "These days, they are only prescribed to treat very severe insomnia." "Reaching the end of the list, we find the two most dangerous drugs in Britain, as ranked by the scientists, one a stimulant, and the other an opiate." "They have a number of things in common." "High levels of harm to the individual, huge consequences on society, and addictive levels of immense proportions, whether physiologically or psychologically." "Those two drugs really win the Oscar for the most harmful substances that we have." "In second place, the stimulant, cocaine." "With 780,000 users in England and Wales alone, its use is on the increase in the UK and every year it causes around 214 recorded deaths." "The use if cocaine in the UK is now as high as it is in America." "I think it's a rather greedy drug - it's very to do with money, snorted with £20 notes, and is to do with a kind of greed... and consumer...and it fuels that." "It's quite a selfish drug." "It turns people in on themselves." "There are two kinds of cocaine." "The powder form, which is snorted, but then also the rock form." "Crack cocaine is a smokeable version of cocaine." "It's a more intense high." "It makes you feel really high for a very short period of time." "Now, that's why people are using it." "It is almost impossible to use crack cocaine without incurring harm." "It's a form of the drug that reaches the brain by smoking or injection very, very rapidly, and that mainlining effect causes a high vulnerability for dependence." "For what it's worth, personally I can do about 37 grams of rock before I fall over." "That's to the point where my addiction got me, that I was of the thoughts that it would never get me like that, and it pulled my pants down and proper gave me a good hiding." "Took eight years of my life away from me." "So, here we are, at number one." "We can finally reveal what the scientists see as Britain's most dangerous drug." "I should imagine it's heroin." "Heroin." "Heroin probably." "Heroin." "Heroin." "Crack or heroin." "Heroin definitely, I'm not going to inject myself..." "I eventually became a heroin addict." "Heroin kills over 700 people a year in the UK alone." "Heroin is the number-one harmful drug, both as a drug itself..." "It's not used by an awful lot of people, but those that do use it, the majority will not be able to use it safely." "Either injected or smoked, heroin is used both as a painkiller and a recreational drug." "It works on the reward pathway, which is why it is intensely habit-forming." "When injected, it can produce a strong feeling of euphoria which is akin to an orgasm, and one dose can last from one to three hours." "As it effects the part of the brain that controls breathing, an overdose can be fatal." "So that's why it's at the top." "It gets in fast, it's very addictive and it's also very dangerous because if you overdose on it then you die." "So, as the most dangerous drug in Britain, why do more than 300,000 people in this country take it?" "If you've ever had a really hard day's work and then you go home and you sit in the comfiest chair you've got, and it just envelops you, and it's like that." "It's just such a nice, warm feeling." "If you're homeless, if you've got a series of things that have gone wrong in your life, if you're in and out of prison, there is no chance of you working, then heroin makes perfect sense." "Because it's a painkiller, it wraps people in a bubble where the pain of life can't get to you." "I wouldn't walk past someone and think, "Look at him, he's a smack head."" "I'd think something might have happened - he could have been a millionaire, you know?" "So, swings and roundabouts, isn't it?" "You know what I mean?" "Shit happens." "Can I have ten one-mil barrels, ten long blue..." "The experts have no doubt that heroin is Britain's most dangerous drug." "It rightfully belongs at the top of the league table of perceived dangerousness in the public eye, and there is enough evidence clinically and scientifically that it's a drug that has a very fierce dependence liability." "Once created, the sense of heroin dependence is very difficult to shift." "We've reached the end of the list, the order of harm in which science sees 20 of the UK's most dangerous drugs." "A list which places cannabis, ecstasy and LSD below tobacco, and which suggests that alcohol, if it were a new drug, would be classified as Class A." "Now we have, I think, a process for assessing drugs, and we can use it to assess new drugs." "We also have, I think, a scale, a ranking of drugs which now needs to go back to the regulators and we need to say to them, "These are the real harms, as best we can estimate them." ""Now how are you going to frame the law to take account of this?"" "The paper on drug harms, I think everybody who's looked at it will rearrange them slightly different." "One of the problems of rank ordering 20 different drugs is the sheer fact that some of them are used in combination." "I think it's very hard to find an objective index of harm, but this might be a start to stimulate some good research." "One thing is for sure, these drugs aren't going away." "I think it's a fact of life that people have always altered their consciousness and they're going to continue doing so." "And therefore we, as a society, need to get a very firm grip on the relative harms of the different substances, which we need to teach to our children, and, rather than forbid, we need to eductate." "Subtitles by Red Bee Media Ltd" "E-mail subtitling@bbc.co.uk"