Abstract Persons living with HIV (PLWH) are an especially vulnerable population in the COVID-19 pandemic given their compromised immune system and comorbidities (e.g., substance use, mental health issues). Currently, no research has examined how the broad impacts of COVID-19 (e.g., extended social isolation, anxiety, family loss) are affecting alcohol use and care engagement in PLWH. Further, it is unclear whether these impacts affect cognition or the brain. This urgent supplement will allow us to capture this window of opportunity and collect timely data to address these gaps. Our ongoing U01 study of a cohort consisting of PLWH and persons without HIV focusing on using a contingency management protocol to reduce alcohol consumption provides many unique strengths to support this supplement. This supplement is within the scope of the parent grant but extents the parent study by incorporating COVID-19-related questions/measures into the ongoing data collection. We will collect additional data through questionnaires, electronic at-home cognitive testing via CANTAB Connect, stress severity quantification via cortisol analysis of hair samples, and qualitative interviews. We will also conduct COVID-19 antibody tests (through blood samples) and MRIs that we conduct as part of the parent grant procedure. The specific aims of this supplement include: 1) Determine the influence of specific psychosocial factors (e.g., social isolation, loneliness, anxiety, and food and housing insecurity) on alcohol use trajectory and HIV-related health behavior and outcomes (ART adherence, and health care engagement) during the period of the pandemic and social distancing. We will also examine which baseline factors (e.g., clinical, demographic, neuroimaging, cognitive) best predict individual differences in outcome; 2) Assess the feasibility and acceptability of (1) an at-home, electronically delivered neurocognitive assessment on the CANTAB Connect system and (2) participant mail-in hair samples. For those willing and able to complete one or both of these measures, we will examine the relationships of the psychosocial factors assessed in Aim 1 on cognitive performance and/or stress severity as measured by cortisol levels from hair samples obtained from participants; 3) Obtain additional neuroimaging from participants to ensure we have data from both before and after the coronavirus crisis, and (should there be sufficient prevalence), determine whether participants found to have been infected with COVID-19 (with or without symptoms) have a greater extent of white matter hypersensitivity (WMH) on FLAIR brain MRI, along with other associated structural, functional, and metabolic brain changes (fMRI, MRS); and an exploratory aim to will conduct a qualitative interview to explore factors that are subjectively judged to be interfering with drinking abstinence and HIV medication adherence, and what might help in this regard. These results will provide valuable evidence on how ...