TRIALS

Mental illnesses are the ‘chronic diseases of the young’ [1], and the mental illness that causes most disability in young people is major depressive disorder (MDD) [2]. The peak period for the incidence of depression (or on-set of new cases) is from 15 to 29 years of age [3], and about 70 % of people will have a subsequent episode of depression after their first episode [4]. Consequently, de-pression affects a larger proportion of the total life course than any other chronic condition [5]. It causes more impairment (measured in disability-adjusted life-years) than any other illness in high- and middle-income countries, and it is projected to be the major cause of disability internationally in all income groups by 2030 as the burden of infectious disease declines [6]. Youth de-pression is associated with disruption in development that has effects across the life course, including under