The lack of empirically sound information about folic-acid efficacy among children with AD, however, also leaves open the possibility that increased supplementation may not be helpful and could, in fact, be harmful. There is some evidence to suggest that high doses of folic acid supplementation produce negative physiological and/or behavioral responses, such as gastrointestinal disturbances, sleep difficulties, malaise/irritability, and excitability/overactivity in a sample of typical adults. Many of these symptoms are similar if not identical to those described more generally in children with AD. Additionally, just as there are favorable anecdotal reports of folic acid treatment, there are negative ones, as well. For example, parents of one teenager with AD told us that, when their son participated in a stepwise-administered supplement program and folic acid was administered as the final supplement, he became extremely agitated, self-injurious, aggressive toward parents, prone to frantic gesturing, and developed sleep difficulties. When the folic acid was withdrawn, his behaviors gradually subsided to a pre-supplementation level (personal communication, September 27, 2003).