Status syndrome by 
The spirit level: why equality is better for everyone by Essay title-specific guidance will be given on what is essential reading when you choose the issue you wish to discuss in your essay.
This will be essay-specific but the following are useful background reading:
Children's Mental Health and Emotional Well-Being in Primary Schools by 
An Introduction to Child and Adolescent Mental Health by 
The sociology of childhood by 
Public Health by 
Social Policy by 
A Reader in Promoting Public Health by 
Debates and Dilemmas in Promoting Health by 
Health and Well-Being in Early Childhood by 
