You may want to check out http://www.additudemag.com/adhd/article/757.html
Exerpt: "Recognition of sleep disturbance in ADHD has been hampered by the misattribution of the initial insomnia to the effects of stimulant-class medications. We now recognize that sleep difficulties are associated with ADHD itself, and that stimulant-class medications are often the best treatment of sleep problems rather than the cause of them."
Some of us have far more serious sleep issues than an herb bought at Walgreens will help.