Compared with patients without HIV, the poorer cognitive performance of people living with HIV (PLWHIV) was partly mediated by a higher prevalence of depressive symptoms and recreational drug use, according to research results published in HIV Medicine.
This cross-sectional study enrolled 637 PLWHIV aged ≥50 years (“older”) and 340 PLWHIV aged <50 years (“younger”) and 276 demographically matched individuals without HIV aged ≥50 as control participants. Participant’s cognitive function was assessed using a computerized battery and their depressive symptoms evaluated via questionnaire.
Both the older and younger groups of PLWHIV scored lower on cognitive assessments (P <.001 and P =.006, respectively) than the older controls after adjustment for sociodemographic factors such as age, gender, ethnicity, and education level. The prevalence of moderate to severe depressive symptoms was 8% in controls. Prevalence of these symptoms was higher in both the older (27%; P <.001) and younger (21%; P <.001) PLWHIV groups.
The two factors associated with lower cognitive function were depressive symptoms (P <.001), and hashish use (P =.01), while alcohol was associated with better scores (P =.02). After further adjusting for these factors, significant differences between older PLWHIV and controls disappeared (P =.08), but differences between younger PLWHIV and controls remained (P =.01).
The cross-sectional nature of the study did not allow for assessment of casual relationships or the direction of associations, which according to the study investigators, is likely to be bi-directional between cognitive performances and depression, alcohol consumption, and recreational drug use. Further, differences in some demographic and lifestyles factors between controls and participants could not be avoided, including the lack of participants <age 50 years who were HIV negative. Despite statistical adjustments for age and demographics, the possibility of unmeasured co-founders influencing the results remains. In addition, the study relied on self-reporting of both depressive symptoms and recreational drug use, thus introducing potential reporting biases.
According to the study investigators, depression and cognitive problems are prevalent in PLWHIV and these results “suggest that comparisons of cognitive performances between PLWH[IV] and HIV-negative controls should take into account depressive symptoms and lifestyle factors.” The researchers further stressed the importance of gaining a better understanding of HIV pathogenesis in the brain and the interaction between infection and mood disorders on cognitive dysfunction.
De Francesco D, Underwood J, Bagkeris E, et al. Depression, lifestyle factors and cognitive function in people living with HIV and comparable HIV-negative controls. [published online February 8, 2019]. HIV Med. doi:10.1111/hiv.12714