‌The overall aim of this study is to evaluate the effectiveness and cost effectiveness of the WISE intervention that provides peer support for secondary school teachers, and teacher training in mental health first aid.

The study will address the following questions:

1. Does the WISE intervention lead to lower levels of teacher depression, absence and presenteeism, improved student wellbeing, attendance and attainment, and reduce student mental health difficulties compared to usual practice?
2. Do any effects of the intervention differ according to the proportion of children receiving free school meals (FSM – an indicator of the socioeconomic catchment area) and geographical area, or individual level baseline mental health, gender, ethnicity and FSM?
3. What is the cost of the WISE intervention, and is it justified by improvements to teacher and student wellbeing and reductions to teacher depression and student difficulties?
4. Does the WISE intervention work according to the mechanisms of change hypothesised in the logic model?
5. Is the WISE intervention sustainable? ‌‌