School leavers are being warned about the dangers of alcohol and illegal drugs after a survey revealed a strong link between the use of both substances.
The survey of clients of The Salvation Army's recovery programs found that 39 per cent of the 309 people questioned were addicted to both alcohol and illegal drugs.
The finding has prompted The Salvation Army to express concern about the high use of alcohol and drugs by teenagers, especially during end-of-school celebrations due to kick-off this weekend.
Program spokesman Major Robert Sneller said the link was disturbing.
"When young people are intoxicated and involved with binge drinking they are more likely to use illegal drugs," he said in a statement.
Major Sneller said teenagers needed to be aware of the dangers of drugs and alcohol.
"Young people place themselves in a very dangerous situation when they are involved in this type of activity," he said.
"There is an increased chance of being involved in accidents and anti-social behaviour which can lead to criminal charges.
"Young women in particular need to realise that the chances of being the victim of assault greatly increases when intoxicated and under the influence of illegal drugs."
The Salvation Army is urging students to buy their own drinks and never leave drinks unattended.
It also said teenagers should help a friend who may be intoxicated by seeking medical help.
Schoolies celebrations begin this weekend for students in Queensland, followed by students from other states during the next few weeks.