That was the surprise finding of the most detailed government-funded study of drug habits. The survey of 5,000 people from Nottingham, Bradford, Lewisham in south London and Glasgow, concluded that wealthier people are more likely to have taken drugs, particularly cannabis, than those from the lower economic groups.
This finding contradicts previous studies that have emphasised drug usage among the poor and deprived, who are the targets of most government and local authority drug-prevention initiatives.
The study, Drug Usage and Drugs Prevention, which was published last December, found that as well as cannabis the middle and upper classes in some cities also used greater quantities of amphetamines, amyl nitrite and magic mushrooms, than lower socio-economic groups.
Heroin and 'crack' cocaine were used more by the low-status groups, as were injected drugs. However, the Independent has learnt that drug agencies in London are beginning to receive calls from middle- class people taking crack. They have been asking for advice on debt problems, mood swings, paranoia and poor health.
This phenomenon is believed to be linked to the increase in telephone ordering of drugs. Buyers will ring their dealer, usually on his mobile phone, to arrange for a delivery. This allows the dealer to carry only a small amount of the cocaine 'rocks' and for the user to avoid being arrested on the street.
There is also evidence that cocaine, which has dropped significantly in price in London from about pounds 60 a gram to as little as pounds 40, is becoming popular again with professionals, particularly in south-east England.
Middle-class drug use has received a major boost with the explosion in the club and rave scene. Illegal substances, particularly ecstasy and LSD, have become an essential part of the dance 'experience'. However, a sharp decline in the purity and novelty of ecstasy has lead many people to switch to more reliable drugs such as LSD, speed and - to a lesser extent - cocaine.
In the survey, 28 per cent of the randomly selected people from bands A and B - professional and managerial workers such as surgeons, bank managers, headteachers, and solicitors - admitted to having taken unprescribed drugs.
In the C1 group - those in white-collar jobs, such as junior doctors, police constables, and teachers - the total was 23 per cent. This dropped to 14 per cent among C2s, Ds and Es - skilled manual workers, semi-or unskilled manual workers and the unemployed and those dependent on state benefits.
Most people said they had little difficulty obtaining drugs. One of the reasons why the drug habits of the middle and upper classes have received so little attention is that the majority of the dealing is done through personal contacts and consumption is private, whereas teenagers and addicts are more likely to buy and use narcotics in public.
Mike Goodman, director of Release, the national drug and legal help line, said: 'We are only beginning to recognise what a high proportion of people from the middle and professional classes use drugs.
'A lot of people don't want to accept that the vast majority of people who use drugs do it relatively responsibly. A large proportion of people on upper incomes can use drugs and hold down demanding and well-paid jobs. These people are not turning to crime and are not encountering major health problems.'