I have been on Luvox (Fluvoxamine) for about 3 or 4 years now for panic attacks/anxiety disorder. Lately, it has seemed like it has stopped working and losing its effect. The past few weeks, I have been feeling "out of it" all day. I have Googled my symptoms and all point to depersonalization & derealization.
I also have had trouble focusing/concentrating the past month or two.
First of all, is it possible for the Luvox to "lose its effect" after this long? And could it be causing these feelings?

Thank you, I appreciate your help!