What are the causes of hallucinations? I have both a/v hallucinations and bipolar disorder. The hallucinations are very disconcerting!

Hallucinations. Hallucinations are psychotic symptoms, and can happen in many different contexts. In bipolar disorder, they can happen when you're either depressed or manic. I see no mood stabilizing or antipsychotic medications in your list, but I do see the antidepressants amitriptylene and bupropion. If this is true, it may be the reason for your hallucinations. Please tell your psychiatrist asap!
Hallucinations. The cause for these false perceptions is not known. There are good medications to control these symptoms.