The contentious debate on evidence-based Global Mental Health care is challenged by the primary mental health program of Jamaica. Political independence in 1962 ushered in the postcolonial Jamaican Government and the deinstitutionalization of the country's only mental hospital along with a plethora of mental health public policy innovations. The training locally of mental health professionals catalyzed institutional change. The mental health challenge for descendants of African people enslaved in Jamaica is to reverse the psychological impact of 500 years of European racism and colonial oppression and create a blueprint for the decolonization of GMH. The core innovations were the gradual downsizing and dismantling of the colonial mental hospital and the establishment of a novel community mental health initiative. The successful management of acute psychosis in open medical wards of general hospitals and a Diversion at the Point of Arrest Programme (DAPA) resulted in the reduction of stigma and the assimilation of mental health care into medicine in Jamaica. Successful decentralization has led to unmasking underlying social psychopathology and the subsequent development of primary prevention therapeutic programs based on psychohistoriographic cultural therapy and the Dream-A-World Cultural Therapy interventions. The Jamaican experience suggests that diversity in GMH must be approached not simply as a demographic fact but with postcolonial strategies that counter the historical legacy of structural violence.