 Major depressive disorder MDD carries worldwide the largest burden of diseases among mental, neurological, and substance-use disorders measured in Disability Adjusted Life Years DALYs, according to the World Health Organization WHO.1 In turn, MDD has the highest DALYs in middle to high income countries, with ischemic cardiac diseases being second.2 Although there are effective treatments for MDD, a large proportion of patients do not achieve remission even after several attempts, and any significant response, when it manifests itself, takes place a delay of a few weeks.3,4 There is always urgency to treat MDD because although patients may have been ill for several weeks, months, and sometimes years, they are often in a crisis situation when they consult. The nature of the crisis may be familial, financialprofessional, or the consultation may take place because of intense personal suffering, possibly involving suicidal ideation. Consequently, rapid therapeutic action and high remission rates represent the two major unmet needs for MDD. 