Janet:

I think you'll have to talk to your psychiatrist about this.

I can tell you this: I took the same medication for over 40 years.  It worked perfectly.  And then one day it just stopped working (right in the middle of a speech I was giving).  When the program was opened for questions I found I didn't understand anything and everything that I was asked.  It was like falling of a cliff.  It has taken my psychiatrist and I approximately three years to find a new cocktail of meds that works for me.  During this period I experienced psuedo-parkinson's symptoms, problems with cognition, excess sedation, anxiety and depression.  It was a bummer.  It was suggested to me that the problem might have been caused as a consequence of the normal aging process, that my brain psysiology might have undergoing changes that rendered the medicine ineffective.  I really don't they know. 

Robin