The primary research focus of the MHBB is the neurologic, neuropsychologic, psychiatric and neuropathologic manifestations of HIV infection. The MHBB conducts a longitudinal, observational study that follows a group of HIV-infected individuals who have agreed to be fluid and organ donors for the purposes of AIDS research. We are currently the largest, multidisciplinary neuroAIDS cohort in New York City, the epicenter of the US HIV epidemic. Our research participants undergo regular neurologic, neuropsychologic, and psychiatric evaluations, and provide body fluid samples that are linked to clinical information. Upon their demise, study participants become organ donors. This program has supplied clinical information, tissue, and fluid samples to over 70 qualified AIDS researchers across America, Europe and Australia. In fulfilling its resource mission, the MHBB functions as part of the National NeuroAIDS Tissue Consortium (NNTC).