A single cause has not beenconclusively proven. Some possibilities are:
2. Brain damage (head trauma) before, after, and during birth (twice as likely to have had labor > 13 hrs)
3. Brain damage bytoxins (internal bacterial and viral, external fetal alcohol syndrome, metal intoxication e.g. lead).
4. Strongly held belief by some peoplethat food allergies cause ADD. This has not been proven scientifically. Feingold's Cookbook for Hyperactive Children explores this belief.