The Catalyst 15.4 Beta drivers are designed especially for GTA V, and support both single and multi GPU setups thanks to the included Crossfire profile. There's no AMD-specific effects included in the game, and early reports indicate the game runs very well on AMD (and Nvidia) hardware.
Aside from GTA V support and the usual bug fixes, AMD has included new Crossfire profiles for Dying Light, Galactic Civilizations III, MGSV: Ground Zeroes, Mortal Combat X, Sleeping Dogs: Definitive Edition; and they've also updated profiles for Battlefield Hardline, Far Cry 4, Shadow of Mordor and Sniper Elite 3.
As usual, you can get the Catalyst Control Center to automatically download and install the latest drivers for you, or you can grab a standalone installer from AMD's driver download page. Don't forget to check back soon, because our GTA V performance article is set to be published in the coming days.