Depressive and anxiety disorders, also referred to as common mental disorders (CMD), are widely prevalent in primary care settings in low-and middle-income countries (LAMIC)(1) and are associated with significant levels of disability, increased health care costs and reduced economic productivity (2-4). Although substantial proportions of primary care attenders in LAMIC suffer from a CMD -estimates vary from 10 to 30% (1,5) -the vast majority of patients do not receive effective treatments (6). This treatment gap persists even as a growing evidence base demonstrates that there are efficacious treatments that are feasible in LAMIC settings (7-10). To address this treatment gap, integration of mental health services into primary care is widely acknowledged as the most feasible strategy (11). While we now have encouraging evidence that specific treatments for CMD work in LAMIC, the challenge is to integrate these in a comprehensive intervention package within routine primary care systems. This is one of the key research priorities for CMD in LAMIC (12).A recent review of evidence from high-income countries highlighted the components that are necessary for the effective integration of services for depression in primary care settings (13). These were the routine screening of patients, education for primary health care staff, skilled mental health providers delivering a stepped-care intervention and the active collaboration of mental health specialists in the programme.The adaptation of these principles in LAMIC primary care settings presents several challenges. These include limited skilled mental health resources, vastly different social and cultural contexts and an already constrained primary care system (14-16). Other barriers to possible integration include the low recognition rates of CMD by primary care doctors (17), limited primary health care staff and large numbers of patients, infrequent and/or inadequate use of antidepressants (18) and the frequent use of medications such as vitamin injections which are prescribed for their supposedly "restorative" properties (19). Low adherence to medication regimens further minimizes the gains of treatment. In addition, few patients receive psychosocial treatments, typically because of a scarcity of personnel with the time and skills to deliver these (20).The MANAS project is an effectiveness trial of a multicomponent, comprehensive intervention to integrate the treatment of CMD in primary care facilities in Goa, a state on the West coast of India which has been the setting for a