The Health Education Board for Scotland believes both findings underline the significance of the "health promoting school" in improving attainment and in meeting the physical and mental health needs of pupils and teachers.
The Lothian study involved 15 women teachers and one man who took part in a five-day outdoor education course in the Cairngorms. The course included workshops on managing change, aspects of mental health and coping strategies. Teacher self-esteem was measured before the course, during it and three months later.
Ian Young, the board's schools programme manager, said self-esteem increased significantly during the course and was largely retained three months later. On average, self-esteem rose by a fifth. Factors included self-worth, appearance, social acceptability, resilience and determination, competence, control over personal destiny and value of existence.
Several teachers reported that they were more able to take control of their lives and developed better relationships with colleagues.
Mr Young said: "Perhaps the time has come to reassess the importance of the health and well-being of one of the most important resources of the learning environment, the teachers."
The staff all had little outdoor experience and told researchers of the sense of achievement at completing non-routine exercises. One said: "I feel so content and good about myself. This will definitely affect my classroom interaction and role and position in the school. I think it is good for the kids too if I feel good about myself."
Three months after the course, staff insisted the greatest changes were personal. Strong friendships were struck with others on the course and many met regularly for social events. But they felt frustrated by the limited change they had been able to introduce at school.
In the international study, Scotland came close to the foot of a World Health Organisation table of 24 European countries. Only Estonia and Slovakia scored lower. Scots are more prone to unhappiness, depression and loneliness.
In Spain, 52 per cent of 15-year-old boys and 33 per cent of girls say they always feel confident, but in Scotland the figures are 20 per cent and 8 per cent.
Boys are more confident and girls are likely to feel confused and lacking self-belief. Other factors related to confidence are feeling positive about appearance, feeling healthy, having supportive friends and environments, not feeling helpless and having good communications with parents, which is specially important for girls.