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Anyone with cognitive issues should get their B12 tested. It should be at a minimum...400pg/ml.

Here is a video to watch:
http://www.youtube.com/watch?v=BvEizypoyO0

Also the clonazepam may be a culprit. The Benzodiazepine family is well known for causing amnesia. This is why they are used in anesthesia, for some medical procedures, and dental extractions.
The patients don't retain a clear memory of the invasive and painful issues during those procedures.

So yes, you could be having cognitive problems. If you are over 50, you could not be clearing the the drug properly and it can build up and cause side effects. These drugs are not recommended anymore in the elderly.