OBJECTIVE: Indigenous communities in the United States and Canada have endured generations of historical trauma. In the face of ongoing marginalization, Indigenous Peoples persist, resist, and thrive. Simultaneously, the consequences of historical trauma are vast and enduring. For instance, there is significant variation in how depression symptoms unfold over the life course. The aim of this study is to examine longitudinal, intergenerational associations between historical trauma and depression symptoms among Indigenous young adults. METHOD: Analyses include data from target participants (ie, children at baseline) and their primary female caregivers (eg, parents) from Healing Pathways (HP), a community-based participatory study that began in 2002/2002 with families from 8 First Nations in the United States and Canada. All eligible children (10-12-years of age at baseline, enrolled tribal members, living on/near reserve land) and at least one of their caregivers were invited to participate, and were interviewed annually for 8 years. Three additional years of interviews were conducted starting in 2017 with baseline-enrolled children, now young adults. Caregivers and their now young adult children completed measures of depression symptoms, family boarding/residential school (BRS) history, and other family sociodemographic variables. RESULTS: Group-based trajectory modeling identified 4 depression symptom trajectory groups: low (28.7%), decreasing (26.6%), increasing (22.4%), and high (22.3%). Multinomial logistic regression analyses, with the low symptom group as the referent group, revealed that familial BRS history doubled the odds of being in the high symptom group (odds ratio = 2.05, p <
.05) compared to the low symptom group. Being female, experiencing discrimination, and caregiver (eg, parental) history of depression increased the odds of being in the high symptom group, whereas experiencing warm and supportive parenting decreased the odds of being in the high symptom group. CONCLUSION: The intergenerational effects of historical trauma remain ongoing and harmful to Indigenous populations. Current findings illuminate several factors that may be particularly salient among subsequent Indigenous generations, and provide implications for prevention efforts. DIVERSITY & INCLUSION STATEMENT: We worked to ensure race, ethnic, and/or other types of diversity in the recruitment of human participants. We worked to ensure that the study questionnaires were prepared in an inclusive way. Diverse cell lines and/or genomic datasets were not available. One or more of the authors of this paper self-identifies as a member of one or more historically underrepresented racial and/or ethnic groups in science. We actively worked to promote inclusion of historically underrepresented racial and/or ethnic groups in science in our author group. While citing references scientifically relevant for this work, we also actively worked to promote inclusion of historically underrepresented racial and/or ethnic groups in science in our reference list. The author list of this paper includes contributors from the location and/or community where the research was conducted who participated in the data collection, design, analysis, and/or interpretation of the work. One or more of the authors of this paper received support from a program designed to increase minority representation in science. While citing references scientifically relevant for this work, we also actively worked to promote sex and gender balance in our reference list.