It really was shame. The fame came too early and he had a toxic family. Britney Spears had the same kind of issues. I'm not sure if it's the fame or family or both, but child stars in the English speaking world rarely do well as adults. Especially those from the 80's and 90's.
It's odd when compared to the Spanish speaking world, those young stars tend to go on to have successful careers and rarely self destruct. It may just be the toxic US culture of fame and materialism. Who knows? I wouldn't have let me kid be a child actor, that much I know...