I really feel for you. My husband has exactly the same symptoms as your son, and is not diagnosed. He started on the lithium aspartate this last year. We have found the dosage which works for him - 10 per day!(5 mg) If he takes less, he gets more manic. I feel it has saved his and my life.
I'm sure it varies with the individual, and maybe some others here can help more.
I'm a little afraid of the lithium orotate, as I have read that it can cause health problems.