''During the peak of that period, I would wake up some mornings worrying about whether I could find some drugs. I would call friends to find out who had got what. And if we realised there was nothing available that day, we would all panic.'' Now Mary can declare she is clean and reformed. She kicked the habit with the help of counselli ng and the Society for the Aid and Rehabilitation of Drug Abusers. She swears she will never touch drugs again.

''No way, this is my new life, I don't want to ruin it,'' she says.

An English girl from a respectable family, Mary looks so healthy you would find it hard to believe that she was addicted to hard drugs.

Her chance of a new life came when a ''drug ring'' at her school was ''busted''.

''I was not surprised at all that the school found out what we were up to. It was so obvious that we were hooked on drugs. We were skipping classes, our school work was not up to scratch and we all looked so unhealthy. It did not take them long to discover what the reasons were for all that,'' she recalls.

The ''ring'' comprised Mary and six schoolmates - two girls and four boys.

''We would get together once a week to have a big bash. We would smoke loads of marijuana, drink excessively and then wind up the day with a big treat of heroin to share among the group members.

''On top of those weekend bashes, I would smoke marijuana three times a day. In my final year with drugs, I could not do without dope for more than 24 hours.'' Mary first tampered with drugs with an occasional smoke of marijuana. This later became a daily routine before she moved on to aerosol inhalation.

But she describes her first use of heroin as ''accidental''.

''I was looking after some heroin for schoolmates. It was left with me for a few days and finally I got overly curious and had a try,'' she explains. From then on, she was taking heroin once a week.

''My heroin addiction was not as bad as many of my schoolmates, some were so hooked they had to take it inside the school toilets.'' According to a government study, most students admit they have easy access to drugs and many say they obtain their drugs from schoolmates and friends.

''Many students have the connections. They don't really do it for money. They consider it a 'friendly buy','' Mary confirms.

''They don't approach students to peddle drugs. If you need a straw [of heroin] or some marijuana, they arrange it,'' she explains.

Mary and her schoolmates often bought marijuana from a young Indian man they met in Kowloon. At the peak of her addiction, she would spend from $500 to $1,000 each week on drugs.

''I used to save up all my pocket money for drugs by not going out at all. Sometimes I would lie to my father that I needed money to buy books or a pair of jeans if I needed extra cash,'' she says.

Despite her association with drugs, Mary insists she was a happy teenager from a happy family.

Her 20-year-old sister had similar problems. She left Hong Kong a year ago and is now studying in Britain.

''My parents love me and my sister very much and I love them just as much. The only thing that has changed between us is they have become more attentive and watchful over me,'' she says.

Mary claims that drug abuse was widespread at her school.

''I personally know at least 15 schoolmates who are regular drug users, most of whom are in the fifth form or above,'' she said.

Mary now has big plans for the future and travelling around the world is her ambition.

''I think if I had not been found out by the school and given a chance to start all over again, I might have turned into a fully-fledged drug addict,'' she said.