Due to very high rates of depression and suicide in The Pacific Island Countries (PICs), there is an urgent need to develop new tools and approaches to identify and provide care to those at risk. In this application we will use modern cognitive science techniques to design and test mobile mental health tools to assist Community Health Nurses, who currently receive little or no training in mental health, for this purpose. To sustain and continuously improve these tools, we will also enhance mobile health research capacity in Fiji (a leading PIC), by training a core group in the principles and practices of mobile health research and development.