You have received a lot of good herbal supplement info, but I'm going to vote with going to the nutritionist. I had similar symptoms and went to my doctor, an MD that practices wholistic medicine, and is a licensed nutritionist. She did all the necessary bloodwork (a lot!) and found that I was not only deficient in several key vitamins and minerals, but also had other issues going on, adrenal distress, hormonal imbalance, Low-T and thyroid disfunction, as well as being allergic/sensitive to several foods. We launched a program of specific supplements, a nutritional diet regimen and abstenance from the offending foods, and an exercise program. It took a couple of years to completely balance, but I began seeing results in memory, concentration and brain function within a couple of weeks. My health recovered and other than still being sensitive to several foods and using a maintenance dosage of vitamin/mineral supplements daily to keep my body stable (I'm in a high stress job!), I'm functioning quite well. Since some supplements can do more harm than good if not taken correctly or monitored, please seek qualified help before you randomly use supplements. It is easy to make things worse rather than improve the situation.