I have bipolar myself and I am beginning to think that it--and/or the meds we take for it can cause these problems. In fact, I was so concerned that I asked to be tested. My results showed "mild cognitive impairment." However, I have had two ministrokes, although they were not in an area associated with memory. But that might suggest some vascular problems in me. That said, my doctor is going to cut down on my Klonopin to see if my memory gets better as a result. Some of the the other bipolar drugs can decrease mental sharpness, too. You might look at what you're taking and do some research. And even depression can cause problems with concentration.