"There are a lot of factors that work here besides the effect of the virus itself. There are social determinants of health. There are comorbid disease states, and there are the clinical effects of HIV. It is difficult to disentangle those. It's difficult to attribute the changes that we see in thinking or in the structure of the brain itself to one factor or another. But I think it's increasingly important to think in those terms, to think in terms of embracing the complexity of aging and trying to understand it with detailed characterization of individual life histories and individual circumstances to look beyond just people with and without HIV and to begin to understand how an individual's life experience affects the health of their cognitive aging."

For more, check out our video Q&A with Dr Petersen, where we take a closer look at his team's recent Lancet HIV study on the impact of clinical, comorbid, and social determinants of health on brain aging in people with and without HIV.