HIV can invade the brain and cause a variety of symptoms. Sometimes this disease is called "HIV encephalopathy" or "AIDS dementia" when the symptoms are severe. It is most common in people who are not on effective HIV medications and when the CD4 cell count is very low.

Symptoms can include:

• memory loss
• depressed mood
• personality changes
• apathy
• unsteadiness when walking
• irritability
• clumsiness
• shaky hands (poor handwriting)

This condition is less common with early and continuous treatment of HIV, but less severe forms of cognitive disease are increasingly recognized.

People who are affected need to have a strong support system. Friends, roommates, or family members can help make sure that HIV medications are taken on time, in the right combination, and at the right dose. If memory is poor, a person can use notes, calendars, and alarms to remember medicines, appointments, and other important events.