Unfortunately, there is no official release of GTA 4 for the PSP. Rockstar Games, the developer of the GTA series, has not announced any plans to port GTA 4 to the PSP. The game was initially released for the PlayStation 3 and Xbox 360 consoles in 2008, followed by a PC version later that year. While there have been rumors and speculation about a possible PSP release, none have come to fruition.