I've been told that it can cause anxiety. The higher the dose the more likely anxiety. I've been on it for maybe 8 years. It works really well for me, and keeps me from smoking (I can smoke just a few puffs now before feeling kind of ill). I take the XL version.

What dose are you on? I take 150 now, but have taken 300 before. I honestly don't feel different on the higher dose. All I know is that if I don't take it for a few days in a row the depression will come back.