Steve-O Back In "Loony Bin" To Straighten Out Life

Steve-O, the star of "Jackass," has checked himself back into a mental institution after living sober for 115 days.

The former MTV star, 33, has written on his blog that after watching himself on Dr. Drew's Celebrity Addiction Special he wants "to explain a little bit of what I've been going through since I got clean, to help some of you understand how much damage drugs and alcohol have really done to me."

Even though he passed the 100-day mark of sobriety, Steve-O says he still suffers from "horrible mood swings and severe depression," from using "so much cocaine, ketamine, pcp, nitrous oxide, and all sorts of other drugs."

He writes that his prescribed medication is not working and he's "back in the looney bin" to try and straighten everything out. He also said, "Everyone's going to make their own decisions in life, but nobody needs to make the same mistakes I made."

In June, he pleaded guilty to cocaine possession but avoided jail time by finishing a drug rehab program.