are 18 years and older

have the capacity to give informed consent as determined by the research nurse

have unexplained cognitive decline (reported either by the patient or an outside informant)

have been on a stable ART regimen for \> 6 months

have an undetectable viral load in plasma for at least 6 months (a single blip of ≤ 150 copies/mL will be accepted)

have not had a change in medications that could potentially interfere with cognition in the past 4 months

COMO: Cognition Study With HIV+ Patients (CTNPT 015)