A report compiled for the Midlands Health Board on the misuse of drugs and alcohol has found that more young people in the region were drinking and in greater quantities.
The study, compiled by a working committee and carried out in second-level schools, found that 48 per cent of teenagers had been offered illegal drugs and 41 per cent believed that between 25 per cent and 100 per cent of their age group took such drugs.
There was a significant association between heavy alcohol consumption and the 16 to 18-year-old age group.
Males were more likely to use drugs than females. It was found that 48 per cent and 59 per cent respectively said that cannabis and ecstasy were "easy" or "very easy" to obtain.
As in similar studies, children in higher income families were more likely to be offered illegal drugs than children from lower income families.
The survey indicated that males were much heavier drinkers and there was no significant difference between teenagers from low or high-income families.
It found that eight out of 10 teenagers between 16 to 18 were drinking and that most started between 14 and 15 years.
Some 56 per cent of them had taken more than five drinks on one occasion.
The committee report said that since the report was compiled in in 1996, it believed this year's figures would be significantly higher.
Alcohol remained the most misused drug in the health board area and up to 81 per cent of patients treated for drug abuse in the psychiatric services were treated for alcohol misuse.
The findings also showed that between 80 per cent and 90 per cent of patients seen by addiction-substance abuse counsellors had also abused alcohol.
The report found that tranquilliser abuse was the second-largest problem after alcohol.
On illegal drug abuse in the area, doctors found that opiates, cannabis and solvents were the main drugs misused.
Heroin accounted for 6 per cent of cases.