I've never heard TBI being connected to ADD or to memory loss but I guess anything is possible with injury to the brain. I've personally struggled with ADD issues my entire life and have developed techniques that have personally helped me deal with the concentration issues associated with ADD. My son also was borderline ADD.
In all my research, consultation with doctors and working with counselors, I've never heard of memory problems being associated with ADD. In fact, most individuals with ADD have incredibly excellent long and short term memories. I'd be curious how your doctor tied the memory tests to ADD.
I've personally found that drugs aren't the answer to ADD. Though many are helped by the drugs, others develop disturbing side effects that negate any benefit to taking the drugs. For me, personally, I managed to develop some techniques that worked very well to help me with my ADD issues.
1. Quiet time of prayer and meditation: as you lay down at night to sleep, take some time to pray about the situation. Petition the Lord for healing. Then, practice clearing your mind of any conscious thoughts. It will be extremely difficult and you'll need to constantly remind yourself to think of "nothing". I don't recommend mantras, but it would probably be fine if you use a comforting scripture. Don't get frustrated that you're having trouble accomplishing this. It could take years to finally reach the point that your training in this area pays off. The primary function for this technique is to teach the brain to focus and ignore intrusive or random thoughts.
2. When working on mundane or routine tasks, put on headphones with calming music. Don't try to sit for ours doing routine tasks - take them in small pieces. The untrained ADD mind cannot concentrate for long periods of time. This will eventually change as you master step 1.
3. When reading, you can retrain your mind to focus by reading a sentence, closing your eyes and restating the basic concept, then moving on to the next sentence. It will slow your reading way down at first, but help you develop the ability to concentrate long enough to actually absorb the material. You will eventually go from one to two sentences, to three, four, etc. When I find my mind wandering while reading, I still have to exercise this technique.
4. Physical activity: Exercise, excercise, exercise. Use the time to focus on a health body and try to focus mentally on each weight you lift, the feeling of your muscles, the rate of your breathing. Again, use it as a tool to renew the body and mind.
5. Fiddling: One method that helps individuals with ADD is to have a small stress ball that you can "fiddle" with underneath the table when working on tasks that require concentration. For some reason, the constant playing with two marbles in your hand, squeezing a stress ball, fiddling with a pen, seems to help people concentrate. I use this all the time and it works very, very well for me. It drives my coworkers crazy when I disassemble my ballpoint pens and put them together, but I've informed them that it really helps me concentrate on the discussions.
6. Healthy diet: It always helps to eat healthy foods. Research has show connections between foods and ADD. Extensive food additives and artificial colors have often been associated with increases in ADD symptoms.
7. Caffeine: Strangely, many people (including myself) will tell you that caffeine helps them concentrate. I've spoken with many others who have reported the same affect.
TBI is a very serious injury. Just recently, the military has started to focus on brain injuries as a legitimate form of disability, see the wounded soldier program search aw2.army.mil
I pray for your healing and hope my tips help. Drugs are not always the cure for ADD. Though my tips have not been tested by psychologists or using medical models, I have found them to work exceptionally well for me.
It has taken years to reach the point that I feel I have the ADD under control, but I can finally thank the Lord that I function well, can concentrate when needed and have excellent retention of information.
Thanks for your service and we'll keep you in our prayers.