RecruitingBehavioural interventionImproving Preschool Outcomes by Addressing Maternal Depression in Head StartWithin a research network of Head Start centers in Massachusetts, an efficacy trial of a stepped-care intervention (SCI) to address maternal depression, using intervention components that both prevent depression and help those in major depressive episode (MDE) engage with care, will be conducted. Both the prevention and engagement components of the model have strong, supportive randomized trial evidence for both their efficacy and safety; but they have yet to be synthesized and tested within a coordinated intervention, applicable to a broad population base. Stepped-care interventions are commonly used in mental health service projects, in which the intensity or type of service is calibrated to the severity of illness.