I am on welbutrin now, and if I miss more than a dose I start to have withdrawal symptoms. I feel horrible.
But I want to add this. Years ago I was on Prozac, and had to stop due to a pregnancy. I went through a hellish six week withdrawal process, Prozac has a long half life. It was horrid. I had migraines and was bedridden for a long time, puked if I rolled over, truly truly awful.
Years later I stopped using Paxil, the withdrawals were shorter lived but worse than the Prozac ones. I never experienced anything like that. Electric zaps through my head, vertigo, nausea. I used to get ill when I missed one dose of Paxil, cutting off it cold turkey was hands down, dead end misery. My doc told me I imagined it all, that just doesn't happen...thousands of others who experienced the same when going cold turkey off those meds beg to disagree.
At the time I didn't really understand about backing down doses etc. So yeah, I was hooked in a powerful physical sense in that if I stopped I was so vastly uncomfortable that without huge motivation to stay stopped, I'd use it again just so I could feel and function normally again. But I was not hooked in the "I feel great! Gimme more!" sense.
I am not sure what sort of "addicted" to you are referring to.