Schizophrenia, depression, epilepsy, dementia, alcohol dependence and other mental, neurological and substance-use (MNS) disorders constitute 13% of the global burden of disease (Table 1), surpassing both cardiovascular disease and cancer1. Depression is the third leading contributor to the global disease burden, and alcohol and illicit drug use account for more than 5% (ref. 2). Every seven seconds, someone develops dementia3, costing the world up to US$609 billion in 2009 (ref. 4). By 2020, an estimated 1.5 million people will die each year by suicide, and between 15 and 30 million will make the attempt5.
The absence of cures, and the dearth of preventive interventions for MNS disorders, in part reflects a limited understanding of the brain and its molecular and cellular mechanisms. Where there are effective treatments, they are frequently not available to those in greatest need. In 83% of low-income countries, there are no anti-Parkinsonian treatments in primary care; in 25% there are no anti-epileptic drugs6. Unequal distribution of human resources — between and within countries — further weakens access: the World Health Organization’s European region has 200 times as many psychiatrists as in Africa7. Across all countries, investment in fundamental research into preventing and treating MNS disorders is disproportionately low relative to the disease burden8.
To address this state of affairs, the Grand Challenges in Global Mental Health initiative has identified priorities for research in the next 10 years that will make an impact on the lives of people living with MNS disorders. The study was funded by the US National Institute of Mental Health (NIMH) in Bethesda, Maryland, supported by the Global Alliance for Chronic Diseases (GACD), headquartered in London. Answers to the questions posed will require a surge in discovery and delivery science. We use the term ‘mental health’ as a convenient label for MNS disorders. We exclude conditions with a vascular or infectious aetiology (such as stroke or cerebral malaria), because these fell within the scope of the two previous grand challenges initiatives — in global health and in chronic non-communicable diseases9.
This initiative differs from previous priority-setting exercises for mental health10–12 in four ways. First, its scope is global. Second, it is the first to employ the Delphi method13, a structured technique using controlled feedback to arrive at consensus within a dispersed panel of many participants. Third, it covers the full range of MNS disorders. Finally, the effort hopes to build a wide-ranging community of research funders — much as the challenge for non-communicable diseases led to the creation of the GACD.