We are building on our prior work in China by performing a phase 4, randomized, controlled clinical trial of the safety and effectiveness of ART that differs in its penetration characteristics in 250 ART-naive individuals who have normal neurocognitive performance. The primary objective will be to determine the effects of better penetrating (BP) ART (zidovudine-lamivudine-nevirapine) compared with worse penetrating (WP) ART (tenofovir-lamivudine-efavirenz) on the prevention of HAND. We hypothesize that volunteers who are randomized to BP-ART will be less likely to neurocognitively decline over 96 weeks of observation than those who are randomized to WP-ART. The secondary objective will be to assess the influence on study outcomes of two conditions: persistent immune activation and viral hepatitis. In an exploratory aim, the project will also assess the influence on study outcomes of a concise panel of drug disposition-associated genetic polymorphisms.