BackgroundIn 2018, the World Health Organization reported that depression is the most common cause of disability worldwide, with over 300 million people currently living with depression. Depression affects an individual’s physical health and well-being, impacts psychosocial functioning, and has specific negative short- and long-term effects on maternal health, child health, developmental trajectories, and family health. The aim of these reviews is to identify evidence on the benefits and harms of screening for depression in the general adult population and in pregnant and postpartum women.MethodsSearch strategies were developed and tested through an iterative process by an experienced medical information specialist in consultation with the review team. We will search MEDLINE, Embase, PsycINFO, CINAHL, and the Cochrane Library, and a randomized controlled trial filter will be used. The general adult review will be an update of a systematic review previously used by the Canadian Task Force on Preventive Health Care for their 2013 guideline recommendation. The search strategy will be updated and will start from the last search date of the previous review (May 2012). The pregnant and postpartum review will be a de novo review with no date restriction. For both reviews, we will search for unpublished documents following the CADTH Grey Matters checklist and relevant websites. Titles and abstracts will be screened using the liberal accelerated method. Two reviewers will independently screen full-text articles for relevance using pre-specified eligibility criteria and assess the risk of bias of included studies using the Cochrane Risk of Bias tool. Outcomes of interest for the general adult population review include symptoms of depression or diagnosis of major depressive disorder, health-related quality of life, day-to-day functionality, lost time at work/school, impact on lifestyle behaviour, suicidality, false-positive result, labelling/stigma, overdiagnosis or overtreatment, and harms of treatment. Outcomes of interest for the pregnant and postpartum review include mental health outcomes (e.g. diagnosis of major depressive disorder), parenting outcomes (e.g. mother-child interactions), and infant outcomes (e.g. infant health and development).DiscussionThese two systematic reviews will offer informative evaluations of depression screening. The findings will be used by the Task Force to help develop guideline recommendations on depression screening in the general adult population and in pregnant and postpartum women in Canada.Systematic review registrationPROSPERO (CRD42018099690)Electronic supplementary materialThe online version of this article (10.1186/s13643-018-0930-3) contains supplementary material, which is available to authorized users.