Does anyone know the truth behind Desmond Harrington (Quinn on "Dexter") weight loss?

This thread has been viewed so many times, and keeps getting resurected because it’s one of the first results in a Google search of “Desmond Harrington’s health” and Desmond Harrington weightloss." That’s how I found it.

I hadn’t seen him since Dexter. I just saw an episode of “The astronauts wives club” and didn’t recognize him. I was trying to figure out why this character was so sick, and why the actor looked familiar. Wow. I don’t know how he looked when this thread was started, but no sane person would call him healthy-looking (or good-looking) now. He’s freskishly thin and sick-looking. His arms are bones with skin stretched over them. He looks terminally ill. I’m sure something is wrong, whether he recognizes or admits it or not.