Hi Susan,
I understand that a deficiency of magnesium can contribute to the onset of anxiety, so supplementing with magnesium can probably work if in fact a person is deficient.
Ginseng, considered an adaptogen, is recommended by some alternative health care practitioners for balancing and maintaining stress levels and we know that anxiety can become the result of too much stress in our lives. However, as the other post from antigone indicated, Ginseng is more associated with increasing energy and not as a treatment for anxiety.
Valerian is used to treat anxiety and insomnia and is often recommended in combination with passion flower to treat anxiety. Another combination that has been proven clinically to treat anxiety is passion flower and lemon balm.
I have spoken with a number of different naturopathic doctors (ND) and I know of one ND that highly recommends and prescribes Rescue Remedy to her patients suffering from anxiety and panic attacks.
Since everyone has different bio chemical make-ups, and there are a number of potential causes that can facilitate the onset of anxiety, I believe the dosages recommended should be left up to the health care practitioner. What works for one person may not work well for another. I believe that recommendations for supplementation should come after the cause(s) of a personâs anxiety has been determined. That way the proper supplementation can be prescribed in the correct combinations and dosages to fit individual need. I also believe a person has a better chance of the supplements working optimally by finding out first what the underlying root cause of their anxiety is.