A long, interesting paper. It says more about what is best for pupils rather than how to achieve it. Here is an interesting snippet, and the link to the full paper is below.
The paper quotes for the prevention of mental health difficulties:
• Prevention: creating a safe and calm environment where mental health problems are less likely, improving the mental health and wellbeing of the whole school population, and equipping pupils to be resilient so that they can manage the normal stress of life effectively. This will include teaching pupils about mental wellbeing through the curriculum and reinforcing this teaching through school activities and ethos;