Ms Forrest, author of Personal Relationships and Developing Sexuality, published by the Scottish Office and distributed to schools, added: "Rarely has an area of the curriculum concerned staff, pupils and parents so much."
But she warned that official guidance on sex education and accompanying support materials were just "a starting point" for staff development. Schools had to be sensitive "to the needs of individual staff members". Many remained embarrassed and concerned about being drawn into talking about their own experiences.
The conference, organised by the Medical Research Council, aimed to encourage a sharing of knowledge on teenage sexual behaviour and of ways to tackle sex education.
Ms Forrest made a plea that this should "not simply be a case of equipping young people with skills and knowledge", but should be about producing "learning opportunities" relevant to the needs of particular groups of children.
Dr Daniel Wight, of the research council's medical sociology unit in Glasgow, said the "current orthodoxy of health education" allowed young people to set the agenda and learn to make responsible decisions. A skills-based, or behaviourist approach, however, is advocated by social psychologists.
Tensions inherent in the two approaches are being studied under Sexual Health and Relationships, a research programme on sex education for 13 to 15-year-olds. The programme, funded by the Health Education Board for Scotland, began in 1994 and has four more years to go.
One interim finding is that pupils between the ages of 13 and 15 are shy of talking about sex. Dr Wight said that classroom discussions had been marked by "long silences" partly because "pupils wish to avoid discussions on details of their own relationships" but mainly because of their inexperience.
He added: "Yet our programmes have been criticised by some health promotion officers for having too old a target group."