The global context
Our healthcare systems are struggling to meet increasing demand for care due to the increasing burden of NCDs \citep{Guzman-Castillo2017} (also see Fig \ref{535015}). In 2017, seventy nine percent of years lived with disability (YLDs) globally are attribtuable NCDs \cite{hub}. Furthermore, prominent NCD conditions include depression and anxiety, common mental disorders associated with 5.05% and 3.18% of global YLDs in 2017, respectively (Fig \ref{535015}). Unfortunately, healthcare systems are still driven by the medical model, which focuses on returning patients to good health (cure), rather than condition management.
Treatment gap and treatment lag (Patel et al., 2010) \citep{Wang2004} are major obstacles to be overcome. The treatment gap relates to the numbers of people who need treatment that are not receiving it, while treatment lag refers to the amount of time taken to receive mental health treatment when it does exist. The treatment gap for mental disorders has been estimated to exceed 50% in all countries of the world, and to reach 90% in those with less resources (Patel et al., 2010). The treatment lag has been estimated to be longer than a decade (Wang, Berglund, Olfson, & Kessler, 2004). These considerations have major societal and economic implications for improving wellbeing of current and future generations.