Box 1 The category fallacy

Medical anthropology has a major influence on the field of global mental health (GMH), with psychiatrist and medical anthropologist, Dr. Arthur Kleinman, conducting the first influential studies [6]. In some cases, anthropological research suggested that mental health diagnoses considered valid in one culture were not valid in populations that experienced and expressed emotions differently—the basis of the “category fallacy,” which led to debate about best practices in humanitarian aid and GMH treatment research. Partially reflecting the influence of medical anthropology, many treatment research studies are tightly indexed to the target population, often preceded by an ethnographically informed needs assessment—emphasizing assessment of the internal validity of diagnosis and treatment for the local/target community. While medical anthropology and ethnographic tools must remain cornerstones of an ethical approach to GMH treatment research, we suggest that implementation science, particularly effectiveness-implementation study designs, can build on this rich history, retaining a focus on internal validity while addressing today’s desperate need for broad scale up of mental health care for common disorders among diverse populations of adults in LMICs