Why did Bradley Nowell break up with Gwen Stefani?

Bradley Nowell and Gwen Stefani never officially dated; they were friends and collaborated musically. Nowell was the lead singer of Sublime, and while Stefani was the frontwoman of No Doubt, their relationship did not evolve into a romantic one. Nowell's struggles with addiction and his untimely death in 1996 ended any potential for a deeper relationship. Stefani has spoken fondly of Nowell, but they remained just friends.