Of 296 volunteers at the San Diego HIV Neurobehavioral Research Center (HNRC) who completed the same test battery over two to six visits, 172 were HIV− controls recruited between 1999 and 2006 and 124 were clinically stable HIV+ individuals recruited through the multi-site CNS HIV Antiretroviral Therapy Effects Research (CHARTER) study between 2001 and 2007. An additional, “validation group” was 111 HIV− volunteers who completed a subset of the same test battery at two time points and 67 who completed the abbreviated battery at three time points at the HNRC between 1987 and 1999. Table 1 compares the demographic characteristics and provide summary results on the NP test battery for the normative HIV− and HIV+ groups and the validation sample.
Neuromedical stability was defined for the HIV+ group as having: ( a) stable HIV disease indicators between visits (i.e., CD4 counts not changing among following categories >500, 500–200, <200; < 1 log10 change in their plasma HIV RNA levels (viral load); and no new AIDS defining illnesses), (b) no change in their antiretroviral regimen, and (c) no incident psychiatric illness (i.e., major depressive episode or substance use disorder) or neurological events (i.e., head injury or meningitis) between visits.
Participants with a history of non-HIV related neuromedical factors that might potentially cause neurocognitive impairment were excluded. These exclusion criteria were (a) head injury with unconsciousness greater than 30 minutes, (b) any known, non HIV related neurological disorders (e.g., epilepsy, stroke), psychotic disorders (schizophrenia) and (c) significant levels of current self-reported substance use, defined as more than three alcoholic drinks per day over the past 30 days, or use of any illegal drugs in the past 30 days. Diagnosis of bipolar disorder was not disqualifying so long as patients were stable on their medications.
Neuromedical stability was defined for the HIV+ group as having: ( a) stable HIV disease indicators between visits (i.e., CD4 counts not changing among following categories >500, 500–200, <200; < 1 log10 change in their plasma HIV RNA levels (viral load); and no new AIDS defining illnesses), (b) no change in their antiretroviral regimen, and (c) no incident psychiatric illness (i.e., major depressive episode or substance use disorder) or neurological events (i.e., head injury or meningitis) between visits.
Participants with a history of non-HIV related neuromedical factors that might potentially cause neurocognitive impairment were excluded. These exclusion criteria were (a) head injury with unconsciousness greater than 30 minutes, (b) any known, non HIV related neurological disorders (e.g., epilepsy, stroke), psychotic disorders (schizophrenia) and (c) significant levels of current self-reported substance use, defined as more than three alcoholic drinks per day over the past 30 days, or use of any illegal drugs in the past 30 days. Diagnosis of bipolar disorder was not disqualifying so long as patients were stable on their medications.
