One in five adults in Northern Ireland has taken illegal drugs according to a cross-border study into substance use.
Cannabis users say they will continue to use the drug
More than 8,000 people took part in the survey, the first of its kind, which was commissioned by the Department of Health and the National Advisory Committee on Drugs, in the Irish Republic.
According to the research, one in five adults in the province have used cannabis, which remains by far the most popular drug.
Of those who took part in the survey, 17% said they had used cannabis at some time.
Ecstasy is the second most popular drug, and has been used by almost 12% of the young adults questioned.
Rob Phipps, the Northern Ireland drug and alcohol strategy co-ordinator, said that young people in the province were much less likely to use cocaine and heroin.
The survey also suggested that men were three times more likely to use illegal drugs than women.