Evening Primrose Oil for Hyperactivity?

What exactly is evening primrose oil used for? Will it calm hyper children? I have been told this would help.

Melvyn Werbach, M.D. in "Nutritional Influences on Mental Illness" (Third Line Press, Tarzana, California, (800) 916-0076 or (818) 996-0076) describes two studies, one of over 90 children and one with 49 children, who were given Evening Primrose Oil (EPO) for hyperactivity with little or no behavioural improvement. One study of 5 children received EPO, 1 to 1.5 grams twice daily, with good results.
The theory in these studies was that hyperactive children may have a deficiency in essential fatty acids which can be supplied by EPO.
For more information on natural ways of dealing with hyperactive children, please go to our website at www.richters.com, select the Q&A area, then choose "Search Richters Q and A" and enter the word "attention" for the search. There is information here on hyperactivity and Attention Deficit Disorder.
For more information on EPO, Judy Graham's, "Evening Primrose Oil" (available from Richters), provides information on how EPO affects the nerves and references to scientific and medical literature for further reading and research.