Listen to more AiC, they had material that was heavier than any Godsmack I've heard, MUCH darker (we're talking mood/atmosphere here), and were always atleast a half step down in tuning. Godsmack started as an Alice in Chains cover band in the Boston area, and never quite grew out of it:

Voodoo=part of Angry Chair with a fill from Over Now, an Inez-ish bassline, and AiC style vocal harmonies.
I could go on.

As for the drug thing, I'll late Layne speak for himself:

"I wrote about drugs, and I didn't think I was being unsafe or careless by writing about them. Here's how my thinking pattern went: When I tried drugs, they were (expletive) great, and they worked for me for years, and now they're turning against me -- and now I'm walking through hell, and this sucks."

People get into hard drugs thinking they're immortal and that they can beat it. Well, they rarely do.