The Prevalence of Neurocognitive Disorder in a Primary Care-based HIV Cohort Compared to a HIV-negative Control Cohort -

HIV positive Inclusion Criteria: * Documented HIV infection * Able to participate in study procedures HIV positive Exclusion Criteria: * Inability to comprehend or read English (as established by the English proficiency questionnaire) * Drug or alcohol intoxicated (as determined by the investigator) * Lack of information in medical records to determine the HAND predictive algorithm (current CD4 count, past CNS HIV-related disease, and duration of HIV therapy) * Life expectancy \<6 months * Inability to attend the clinic for required study follow up visits HIV-negative Inclusion Criteria: * Negative HIV-1 test within 12 months of study entry HIV-negative Exclusion Criteria: * Life time traumatic brain injury leading to loss of consciousness of at least 30 minutes. * Inability to comprehend or read English (as established by the English proficiency questionnaire). * Inability to attend the clinic for required study follow up visits. * History of chronic neurological illness. * Unstable psychiatric conditions such as bipolar disorder or depression. * Individuals with psychiatric disorder on the psychotic axis. * Active or past (within the last 6 months) severe alcohol or substance abuse sufficient, in the investigator's judgement, to prevent completion of tests or Inability to attend for the planned required study follow up visits.