Cumulative burden of depression and domain-specific cognitive impairment over time in the women's interagency HIV study: A marginal structural model approach

Background Women with HIV (WWH) experience high depression rates and cognitive impairment. Biological models suggest that depression is a scar on the brain, but large longitudinal studies on its specific cognitive effects are scarce. WWH may be more susceptible to these effects than women without WIH (WWoH). We estimated the association between depressive symptoms and domain-specific cognitive impairment in the Women's Interagency HIV Study. Methods Participants were followed until cognitive impairment onset. Depression burden was calculated using Center for Epidemiologic Studies Depression scale (CES-D) scores. We interpolated CES-D scores into proportion values and used them with the time elapsed between visits to calculate the percent of days with depression (PDD). Domain-specific cognitive impairment was defined as 1-SD below mean performance in each domain attention/working memory, verbal memory, verbal learning, executive function, processing speed, verbal fluency, and motor function. Marginal structural Poisson models were used to estimate incidence rate ratios (IRRs) of cognitive impairment. Results Among 2536 participants (1757 WWH; mean age = 45.7 y; 71 % non-Hispanic Black; 18 % Hispanic), the average PDD over 12.8 years was 23.4 %. Overall, a 1-SD above mean PDD (i.e., 23–48 % increase) was associated with higher risk of impairment in attention/working memory (IRR = 1.24; 95 %CI: 1.08, 1.44), executive function (IRR = 1.43; 95 %CI: 1.18, 1.72) and verbal learning (IRR = 1.20; 95 %CI: 1.05, 1.37). HIV serostatus did not modify these associations. Conclusions Low-income women of color spend 23 % of their lives with depressive symptoms, a burden contributing to cognitive impairment. Addressing mental health is crucial for optimizing cognitive health.