I read Running With Scissors awhile ago and loved it, but felt bad about loving it. Burroughs is a very comedic man, his timing and writing are very spot-on. However, the subjects that he writes about, his life, are just so depressing that you laugh... but then feel bad.
Dry is his memoir about being an alcoholic, getting sober and struggling with whether to jump back off the wagon or not. It also intertwines his friends into his story and shows their struggles with various vices as well. This sounds serious and, for the most part, it is. But Burroughs injects quite a bit of humor into the writing, as per normal.
One of the things I've read about Burroughs, and he mentions briefly in this book, is that he has kept detailed journals over his life. So what you are reading is pulled from those journals and you really don't need to worry about another James Frey. (Although the Running With Scissors family apparently disputes this)