To conduct comparative research on the implementation and scale-up of evidence-based mental health interventions in low- and middle-income settings. Mental, neurological, and substance use disorders are common in all regions of the world, affecting every community and age group across all income countries. While 14% of the global burden of disease is attributed to these disorders, most of the people affected – 75% in many low-income countries – do not have access to the treatment they need.