I don't know. I have had more word finding and spelling issues. How old is he? Surely, the doctor should be told about this. The medications often taken for this illness (neuroleptics, pain meds) certainly can cause a person to be "out of it!" I have tightened up my eating habits (NO SUGAR or junk food of any kind) and I also take my vitamins. I have mentioned on these boards a supplement I take called PS 100 many times. I understand it is used in Europe to help with memory issues. Probably should check with his doctor first to see if he can take it. Anyway, it has helped me a little with the memory issues caused by my medications. I take two tablets a day. You can read reviews about it at: www.iherb.com. Generally, it seems very safe and I understand it is used in other countries for ADD or dementia. Anyway, I would double check dosages, consider tightening up on diet and consider that supplement (if the doc says it is ok). Also, make sure your father is getting enough rest and is not depressed. Bad pain can interrupt sleep and make one very depressed. My goodness, until my pain got more controlled, I was VERY depressed and could barely think. I still have my bad days, but less so at this time and I am very grateful. Hang in there!