Is it because of my medication?

I have been diagnosed with Bipolar DIsorder and ADHD two years ago. For two years I've been on different mood stabilizers (was on anti-depressants too, but now I'm off them), and currently I am on an anti-psychotic Invega, and a mood stabilizer Lamictal. Anyhow, I've noticed that when I was put on medication, I gradually became very apathetic and indifferent about everything. I lost interest in most things... and now I feel very stupid because I feel like my once sharp mind became very dull. Is this due to my medication? I wanna be smart again. If I get off my medication, will I get inspired again and recover the intelligence that I have lost? Also, since that I have ADHD and I'm not being treated, I feel like it is getting worse because I've been suffering from low attention span. AHHHH!!! What can I do?!! I DON'T WANT TO BE STUPID, PLEASE HELP!!