The Big Question: What is the truth about skunk, and have the dangers been overstated?

Why are we asking this now?

Yesterday, the Advisory Council on the Misuse of Drugs began reviewing scientific evidence on the classification of cannabis, amid widespread fears that Britain is in the grip of an epidemic of cannabis-induced psychosis. This view is based on the belief that cannabis sold on the streets is stronger than it was a generation ago and is tipping vulnerable people into mental illness, including schizophrenia.

The review, the second in two years, was ordered by Gordon Brown, who has indicated he is minded to reverse the decision of the former Home Secretary David Blunkett, who downgraded the drug from Class B to Class C in 2004. Mr Blunkett's aim was to free up police time squandered on prosecuting users, but the Prime Minister is concerned that the move sent the wrong message to young people, who are now confused about drug laws.

What is skunk?

It is the generic name given to potent strains of the cannabis plant containing the highest levels of the psychoactive ingredient tetrahydrocannabinol (THC). The original skunk, a cross between the fast-growing Indica and the potent Sativa strains, is believed to have originated in the US and was so called because of its pungent smell. Dutch growers have since refined and cross-bred the plants to produce a number of strains including super-skunk, Early Girl, Northern Lights and Jack Herer. They are normally grown indoors under lights, or in a greenhouse. The more intensive the cultivation, the higher the THC content.

How strong is skunk?

Traditional herbal cannabis contains 2 to 4 per cent THC, according to the Drugscope charity. More potent varieties average 10 to 14 per cent – three to four times as strong. Claims that skunk is 20 to 30 times as powerful as herbal cannabis are exaggerated. A European review of cannabis potency in June 2004 concluded that the overall potency of cannabis products on the market had not increased significantly because imported cannabis dominated the market in most countries. However, as home-grown cannabis has become more widely available, especially in the Netherlands and Britain, consumption of stronger varieties has increased. The Home Office yesterday claimed that 70 per cent of cannabis sold on the streets of Britain was skunk.

Why is skunk so popular?

It offers a powerful high, similar for some users to that obtained with ecstasy or LSD but without the chemicals. Even in the world of recreational drugs, users prefer a "natural" high. It can be home-grown from legally obtainable seeds – many users grow a few plants on a windowsill for personal consumption. It is easy to identify, making it difficult to fake. Cannabis resin, by contrast, has been adulterated with everything from boot polish to the horse tranquilliser ketamine.

How dangerous is skunk?

This is an area of intense dispute. The greatest concern is over its effects on mental health. When the advisory council last reviewed cannabis in early 2006, it concluded that use of the drug by existing schizophrenia sufferers might worsen their symptoms and lead to a relapse in some. But on causation, it said: "The evidence suggests, at worst, that using cannabis increases the lifetime risk of developing schizophrenia by 1 per cent."

Some scientists believe this underplays the risks. Professor Robin Murray, of the Institute of Psychiatry in London, says that in vulnerable individuals – those with an unsuspected genetic predisposition to schizophrenia – cannabis may be the trigger that starts a full-blown mental illness.

His research showed that up to 10 per cent of the adult population – or about four million people – are prone to paranoid thoughts or grandiose ideas and, among those who smoke cannabis regularly, half may be tipped into psychotic delusions and end up needing treatment. The early age at which people start smoking the drug today, compared with two or three decades ago, is an additional concern, he says, because their brains may be more vulnerable.

Have the risks been overstated?

Yes. A recent report, printed in several newspapers last month, suggested that 500 people a week were being admitted to hospital for treatment for the effects of cannabis – a 50 per cent increase since the drug was downgraded to Class C in 2004. The figure was repeated in reports this week. Drugscope said the figure, quoted by the Public Health minister Dawn Primarolo, was actually related to the number of people consulting community drug treatment services for help or advice where "treatment" may amount to no more than an informal chat. The actual figure for hospital admissions was 14 per week in 2006-07 – and that was lower than the year before.

So why did the advisory council recommend that cannabis remains a Class C drug?

Because, despite the evidence of a link with schizophrenia, it concluded that cannabis remained "substantially" less harmful than the Class B drugs amphetamines and barbiturates. The classification of drugs is, in part, about proportionality. Experts have long argued that the current system for ranking drugs – Class A for the most dangerous to Class C for the least dangerous – is irrational. In terms of harm caused, alcohol and tobacco are more dangerous than cannabis, yet they are legal and cannabis is illegal. Defenders of the 2004 decision to downgrade cannabis to Class C say that it has not increased its use and it has freed police to tackle drug-dealers and other more serious crimes. Since 2004, consumption of cannabis has actually declined.

Are there other risks from skunk?

Yes – but they are small. Skunk is smoked like cannabis, contains carcinogenic substances and is often mixed with tobacco. The British Lung Foundation estimated that smoking three joints was equivalent to smoking 20 cigarettes but most users give up after a few years. Some experts also believe there is a risk of dependence among regular smokers. However, cannabis is not seen as a drug of addiction like heroin or tobacco.

The greatest fear, alongside its effect on mental health, is that skunk may lead people on to use harder drugs. It is certainly true that many people who become heroin addicts have used cannabis in the past. But the vast majority of cannabis users never progress to heroin. Research by the Home Office concluded that the so-called "gateway effect" of cannabis – leading users on to harder drugs – was probably "very small".

Should the newer, more potent forms of cannabis be re-classified?

Yes...

* Vulnerable individuals with a predisposition to mental illness may be tipped into psychosis by the drug

* The younger age at which people start smoking means their brains are more vulnerable

* Skunk cannabis is three to four times stronger than herbal cannabis and has more potent effects

No...

* At worst, the experts say, the use of cannabis increases the lifetime risk of schizophrenia by only 1 per cent

* The chances that users of skunk will progress to harder drugs such as heroin are very small

* Skunk is safer than alcohol and tobacco, which are legal and cause more than 100,000 deaths a year

Suggested Topics
Sport
Premier League Live
footballLIVE Follow all the Premier League action as it happens
Life and Style
3D printed bump keys can access almost any lock
gadgets + echSoftware needs photo of lock and not much more
News
i100
News
The slice of Prince Charles and Princess Diana's wedding cake and the original box from 29 July 1981
newsPiece of Charles and Diana's wedding cake sold at auction in US
PROMOTED VIDEO
Life and Style
ebooksA superb mix of recipes serving up the freshest of local produce in a delicious range of styles
Life and Style
ebooksFrom the lifespan of a slug to the distance to the Sun: answers to 500 questions from readers
News
James Argent from Towie is missing, police say
peopleTV star had been reported missing
Arts and Entertainment
Gregg Wallace in Summer's Supermarket Secrets
tv All of this year's 15 contestants have now been named
News
i100(and it's got nothing to do with the Great British Bake Off)
Arts and Entertainment
Inside the gallery at Frederick Bremer School in Walthamstow
tvSimon Usborne goes behind the scenes to watch the latest series
Life and Style
A picture taken on January 12, 2011 shows sex shops at the Paris district of Pigalle.
newsThe industry's trade body issued the moratorium on Friday
Arts and Entertainment
Could we see Iain back in the Bake Off tent next week?
tv Contestant teased Newsnight viewers on potential reappearance
Life and Style
Silvia says of her famous creation: 'I never stopped wearing it. Because I like to wear things when they are off the radar'
fashionThe fashion house celebrated fifteen years of the punchy pouch with a weighty tome
News
i100Steve Carell selling chicken, Tina Fey selling saving accounts and Steve Colbert selling, um...
Voices
The Ukip leader has consistently refused to be drawn on where he would mount an attempt to secure a parliamentary seat
voicesNigel Farage: Those who predicted we would lose momentum heading into the 2015 election are going to have to think again
Arts and Entertainment
Cara Delevingne made her acting debut in Anna Karenina in 2012
film Cara Delevingne 'in talks' to star in Zoolander sequel
Sport
Mario Balotelli pictured in his Liverpool shirt for the first time
football
News
i100
Independent
Travel Shop
the manor
Up to 70% off luxury travel
on city breaks Find out more
santorini
Up to 70% off luxury travel
on chic beach resorts Find out more
sardina foodie
Up to 70% off luxury travel
on country retreats Find out more
Latest stories from i100
Have you tried new the Independent Digital Edition apps?

ES Rentals

    Independent Dating
    and  

    By clicking 'Search' you
    are agreeing to our
    Terms of Use.

    iJobs Job Widget
    iJobs General

    Clinical Negligence Solicitor

    Highly Competitive Salary: Austen Lloyd: HAMPSHIRE MARKET TOWN - A highly attr...

    Network Engineer (CCNP, CCNA, Linux, OSPF, BGP, Multicast, WAN)

    £35000 per annum: Harrington Starr: Network Engineer (CCNP, CCNA, Linux, OSPF,...

    Commercial Property Solicitor - Bristol

    Highly Attractive Package: Austen Lloyd: A VERY HIGH QUALITY FIRM A high qual...

    DevOps Engineer (Systems Administration, Linux, Shell, Bash)

    £50000 per annum: Harrington Starr: DevOps Engineer (Systems Administration, L...

    Day In a Page

    Ukraine crisis: The phoney war is over as Russian troops and armour pour across the border

    The phoney war is over

    Russian troops and armour pour into Ukraine
    Potatoes could be off the menu as crop pests threaten UK

    Potatoes could be off the menu as crop pests threaten UK

    The world’s entire food system is under attack - and Britain is most at risk, according to a new study
    Gangnam smile: why the Chinese are flocking to South Korea to buy a new face

    Gangnam smile: why the Chinese are flocking to South Korea to buy a new face

    Seoul's plastic surgery industry is booming thanks to the popularity of the K-Pop look
    From Mozart to Orson Welles: Creative geniuses who peaked too soon

    Creative geniuses who peaked too soon

    After the death of Sandy Wilson, 90, who wrote his only hit musical in his twenties, John Walsh wonders what it's like to peak too soon and go on to live a life more ordinary
    Caught in the crossfire of a cyber Cold War

    Caught in the crossfire of a cyber Cold War

    Fears are mounting that Vladimir Putin has instructed hackers to target banks like JP Morgan
    Salomé's feminine wiles have inspired writers, painters and musicians for 2,000 years

    Salomé: A head for seduction

    Salomé's feminine wiles have inspired writers, painters and musicians for 2,000 years. Now audiences can meet the Biblical femme fatale in two new stage and screen projects
    From Bram Stoker to Stanley Kubrick, the British Library's latest exhibition celebrates all things Gothic

    British Library celebrates all things Gothic

    Forthcoming exhibition Terror and Wonder: The Gothic Imagination will be the UK's largest ever celebration of Gothic literature
    The Hard Rock Café's owners are embroiled in a bitter legal dispute - but is the restaurant chain worth fighting for?

    Is the Hard Rock Café worth fighting for?

    The restaurant chain's owners are currently embroiled in a bitter legal dispute
    Caribbean cuisine is becoming increasingly popular in the UK ... and there's more to it than jerk chicken at carnival

    In search of Caribbean soul food

    Caribbean cuisine is becoming increasingly popular in the UK ... and there's more to it than jerk chicken at carnival
    11 best face powders

    11 best face powders

    Sweep away shiny skin with our pick of the best pressed and loose powder bases
    England vs Norway: Roy Hodgson's hands tied by exploding top flight

    Roy Hodgson's hands tied by exploding top flight

    Lack of Englishmen at leading Premier League clubs leaves manager hamstrung
    Angel Di Maria and Cristiano Ronaldo: A tale of two Manchester United No 7s

    Di Maria and Ronaldo: A tale of two Manchester United No 7s

    They both inherited the iconic shirt at Old Trafford, but the £59.7m new boy is joining a club in a very different state
    Israel-Gaza conflict: No victory for Israel despite weeks of death and devastation

    Robert Fisk: No victory for Israel despite weeks of devastation

    Palestinians have won: they are still in Gaza, and Hamas is still there
    Mary Beard writes character reference for Twitter troll who called her a 'slut'

    Unlikely friends: Mary Beard and the troll who called her a ‘filthy old slut’

    The Cambridge University classicist even wrote the student a character reference
    America’s new apartheid: Prosperous white districts are choosing to break away from black cities and go it alone

    America’s new apartheid

    Prosperous white districts are choosing to break away from black cities and go it alone