reservoir for the virus. Post mortem examination of brain tissue has provided evidence of eNS cell damage in 80%-90% of people who die with AIDS. For about 10%-20% of people with AI DS, mild neuropsychological symptoms are the first signs of the disease. Approximately 20% of individuals infected with HIV-1 develop AIDS dementia complex. The symptoms include apathy, difficulty concentrat­ ing, irritability, depression, and personality changes. In the later stages of the disease, people may experience psychiatric disor­ ders. Death usually occurs within 6 months of the appearance of those more severe symptoms. Up to 90% of children infected with H IV-1 experience attention and concentration difficulties and often experience neurodevelopmental delay or regression over time.