Hi there, Thanks for your query. I wish you had mentioned the nature of heart problem and drugs prescribed for the condition. I am also not aware of her age. Mirtazapine does not cause behavioral abnormalities. This drug should NOT BE STOPPED ABRUPTLY. From the brief information available, the possibilities are :- * A possible bipolar disorder, the symptoms of which are somewhat similar to those of your wife. You should therefore consult a Psychiatrist who will thoroughly evaluate her; diagnose her mental disorder and prescribe specific medicines which do not interact with those for the heart. * If she is post-menopausal, then Post-Menopausal Syndrome (PMS) cannot be ruled out. In that case, hormone replacement therapy will be beneficial. The Gynecologist would be the right specialist to consult for this. * In a few types of heart problems, small clots are formed inside the heart cavity. These clots sometimes, get dislodged and flow to the brain, cause blockage of brain vessels, leading to several pin-head sized infarcts in the brain. Further, if your wife is on drugs which prevent blood clotting, possibility of bleeding in the brain cannot be ruled out. In both cases, brain function suffers. Consult your doctor and apprise him of my opinion. I am certain that he agree with me, order required tests, and- based on the reports- will prescribe suitable treatment as advised. Or, he may refer your wife to the relevant specialist (Psychiatrist, Gynecologist or Cardiologist). If you find my response helpful and informative, do not forget an “excellent” rating to my answer, to encourage all doctors- engaged in social service- to render sound advice to the FREE queries. Fond regards and have a nice day Dr. Rakesh Karanwal