Work carried out under the Health Behaviour in School-aged Children (HBSC) survey suggests that social stresses can have as big a part to play in health inequalities as smoking, poor diet and alcohol consumption.
Ian Young, development consultant with NHS Health Scotland, will tell a World Health OrganisationHBSC forum in Florence that Scottish children have become happier in the past decade, but still lack confidence.
This is the first in a series of international forums to support greater action on young people's health, and Scottish Executive strategies such as the health promoting school and Hungry for Success will form a case study.
Mr Young told The TES Scotland he hoped the review of the curriculum, which is likely to give a greater focus to health education, would ask whether school was a place that children liked to go to, especially more vulnerable children.
"If they feel school is a nice place to be, there is evidence that that is related to lower smoking, drug-taking and alcohol use," he said.
A key factor among the NEET group who leave school and are not in education, employment or training was whether there was genuine respect and understanding in their relationships with adults.
Mr Young quoted an American observation: "Kids don't learn from teachers they don't like." The word "respect", however, should be substituted for "like", he said.
"This is not to criticise teachers but, if a young person's family life is very damaged, then the impact of the adults working with them can be great - so this area represents a huge challenge," Mr Young said.
"If they feel the adult actually wants to help them, that seems to be very important."
Mr Young also reported a gap between how adults and young people perceived health. Adults tended to focus on physical health and physical activity, whereas young people saw health more as a mental and social issue.
"When you ask young people what concerns them, it is things like physical appearance, relationships, achievement, social activities and well-being,"
The HBSC study results from 1997-98 showed that life satisfaction is highest among 11-year-olds and at this age there is no gender difference.
But, by the time they are 15, girls have a significantly lower score than boys.