The impact of changes in social determinants of health on adolescent and young adult mental health during the COVID-19 pandemic: A longitudinal study of the Asenze cohort in South Africa

Social determinants of health (SDOH), such as education, employment, housing, and food security, were all impacted by the COVID-19 pandemic and associated lockdowns. These changes to SDOH were particularly impactful in low-and-middle-income countries (LMIC) such as South Africa in which populations have a high risk of exposure to adversities that were exacerbated by COVID-19 lockdowns (e.g., economic instability, violence, family separation and loss). Although several studies conducted during the pandemic linked lockdowns and changes in SDOH to adverse mental health outcomes, these studies were predominantly cross-sectional, which precludes the ability to evaluate: i) the impact of changes in SDOH on mental health over time; ii) whether initial impacts of COVID-19 persist long-term; and iii) the mechanisms through which changes in SDOH impact mental health, which are necessary for identifying potential intervention points. Further, adolescents and young adults (AYA; ages 18-25) have not been a major focus of COVID-19 mental health research, which is a gap because this is an age range during which individuals finish education and transition into new roles, both professional and personal. This period is also when incident mental health disorders often first occur and shapes the probability that they will continue. This study addresses these gaps by leveraging an existing large, population-based cohort of over 1100 AYA and their caregivers in in South Africa, the Asenze cohort. Four waves of data collection through 2022 have captured longitudinal measurements on mental, behavioral, and physical health outcomes as well as SDOH correlates. This provides a rare opportunity to investigate changes in AYA mental health before, during, and after the height of the pandemic in a LMIC that has been substantially impacted by COVID-19 – South Africa has experienced the highest number of COVID-19 cases, deaths, and excess mortality due to the pandemic in Africa. In this mixed methods study, we will investigate the impact of COVID-19-related SDOH changes on mental health among AYA in the Asenze cohort. Specifically, we will model changes in mental health outcomes from pre-COVID-19 and the acute COVID-19 phases (Asenze Wave 3, collected 2020-2021 and Wave 4, collected 2022) to the post-acute COVID phase (Wave 5, 2024-2025) and how these changes may have been impacted by SDOH (e.g., access to education, employment, availability of health care, food security, exposure to violence). We will examine mechanisms (mediators) underlying the relationship between SDOH and mental health and key populations (moderators) to foster resilience. Qualitative data building on prior qualitative and quantitative data, will provide an in-depth, complementary, and contextual understanding on AYA mental health during and COVID-19 and perceptions on the acceptability and appropriateness of interventions that target mechanisms and key populations identified in the quantitative data. The findings will provide near-term information on possible intervention points through which SDOH impacts mental health in the context of COVID- 19, and long-term information to inform intervention approaches in future public health emergencies.