Parents need to do more to provide clear boundaries and strong role models for their children, according to a major survey of Scottish youth.

The study, carried out for YMCA Scotland, found that young people were more likely to emulate their peers than their parents, and only 27% said they were set clear rules and consequences at home.

Many reported high-risk behaviour, such as drinking, drug-taking and under-age sex. One in five had skipped school at least once in the past four weeks, while 14% of boys and 21% of girls said they were frequently depressed or had attempted suicide, or both.

Some 41% of boys and 40% of girls admitted they had drunk alcohol three or more times in the past month or had been drunk at least once in the fortnight before completing the study.

A total of 26% of girls and 22% of boys said they had engaged in either bulimic or anorexic behaviour.

The questionnaire, completed by more than 5000 pupils in 10 secondary schools in Glasgow and , included "lie detector" questions designed to weed out boastful or exaggerated responses - 429 responses were rejected for this reason - and researchers believe the findings are reliable.

The research, carried out by the Search Institute of Minnesota, is designed to build a profile of the strengths and weaknesses of young people in Scotland. The study has been used extensively in the US, where more than three million young Americans have already been assessed to measure their "assets" and negative behaviours or "deficits". This is the first time the system has been used in Europe.

The YMCA's goal is to enhance the resilience factors of young people and the supports they have within communities, to protect them and divert them from antisocial and high-risk behaviours. A conference in Perth tomorrow will be tasked with taking the findings forward in a Scottish context.

Ian Marr, chief executive of Perth YMCA, said: "We want to look at what can be done in communities so that young people are less likely to engage in the deficit' activities."