Up to 16% of Aids sufferers develop a form of dementia caused by viral damage to the white matter of the brain. This usually occurs in the later stages of the disease

Aids Dementia Complex (ADC) shows features of clinical depression in the early stages of development, especially apathy. Later stages of this dementia are memory loss and mobility problems

Diagnosis relies heavily on the judgement of medical staff treating the disease. Tests include neuroimaging, lumbar punctures and Mini-Mental Status Examination

As this is a viral infection, prevention techniques include the use of AZT, 3TC+D4T, nevirapine -- drugs that cross the blood/brain barrier

AZT is used to treat the condition, also known as zidovudine, brand name Retrovir®

Further information available here:

http://www.aegis.com/pubs/gmhc/1992/gm060202.html

http://www.sfaf.org/treatment/beta/b31/b31adc.html