ABSTRACT
Despite the use of effective antiretroviral therapy (ART), HIV-related neurocognitive impairment (NCI)
continues to be prevalent among people living with HIV. For more than 20 years, our investigation of HIV-
associated comorbidities among African Americans (AAs) has demonstrated that while comorbidities are
prevalent among AAs living with HIV, other factors, such as cocaine use, may trigger or accelerate their
impact. We have shown that although HIV increases the risk of coronary plaque, the detrimental effect of
HIV/ART predominantly affects cocaine users rather than non-users. Likewise, our preliminary work showed
that while HIV was associated with NCI, the adverse effect of HIV primarily impacted cocaine users.
Furthermore, our ongoing HEART study showed that a contingency management (CM) intervention is effective
in achieving a sustained reduction in cocaine use among AA cocaine users with subclinical heart disease and
was associated with a concurrent decrease in coronary plaque burden. Cocaine use and NCI continue to
disproportionately affect AAs, especially those living with HIV. As of now, there are no FDA-approved medications
for cocaine addiction. We propose to investigate whether CM can be employed to decrease cocaine use and
slow cognitive decline among AA cocaine users. There is no single definitive biomarker that can measure
cognitive decline; however, brain MRI may detect early structural changes in the brain that signify cognitive
decline, prior to the onset of symptoms. Our latest brain MRI study revealed an independent association
between cocaine use and the length of its use with an increased severity of white matter hyperintensities
(WMH) and a decrease in hippocampal (HP) volume among AAs. WMH are recognized as one of the most
promising brain MRI markers of cognitive decline along with HP volume. Thus, we propose a 5-year study to
evaluate the effects of a 12-month CM intervention on the brain MRI biomarkers and cognitive performance
assessed with NIH Toolbox Cognition Battery (NIHTB-CB) among AA cocaine users. We will recruit 180 AA
cocaine users, =40 years of age, including an equal number of men and women with and without HIV, drawn
from our ongoing study (U01DA040325). Participants will undergo a 12-month CM to reinforce cocaine
abstinence with an escalating cash incentive approach. In Aim 1, we will evaluate the effects of a 12-month CM
on MRI measures of brain structure and function (WMH, HP volume, resting state fMRI and other measures)
and cognitive performance (NIHTB-CB). In Aim 2, we will evaluate the net effect of HIV on brain MRI measures
and cognitive performance. In Aim 3, we will study whether changes in brain MRI measures during the 12-
month CM period are associated with changes in cognitive performance. This study will establish the
effectiveness of a targeted intervention in reducing cocaine use and improving cognitive outcomes in AA
cocaine users living with HIV, thereby addressing a recognized health disparity in the AA population.
