With nearly 6 million children diagnosed with the condition according to the Centers for Disease Control and Prevention, it's a fair question, especially when we consider children often take these drugs for many years.
One of my favorite magazines, Mind by Scientific America, delves into the issue in a balanced manner in Do ADHD Drugs Take a Toll on the Brain? This is good science reporting - many of the writers are trained scientists, often working researchers. If you love all matters related to the brain, psychology, and the like, add this to your reading roster.
Here's the "about the authors" from the foot note:
Edmund S. Higgins is clinical associate professor of family medicine and
psychiatry at the Medical University of South Carolina and co-author, with Mark
S. George, of The Neuroscience of Clinical Psychiatry (Lippincott Williams &
Wilkins, 2007) and Brain Stimulation Therapies for Clinicians (American
Psychiatric Publishing, 2009).
As for the ADHD drug diagnosis, there's much speculation, many animal studies and fewer human ones. The drugs, which are amphetamines, have been linked to mood disorders, mainly depression and anxiety. Research has yet to fully tease out the reasons for these correlations. The more solid evidence - stunted growth from both human and animal studies. The latter also hint at cognitive impairments such as memory problems and hallucinations in large doses. There's also some evidence of a link between amphetamine use and Parkinson's disease. Basically, except for the stunted growth findings, everything else is inconclusive when it comes to regular use in children.
And why do I trust these conclusions? The authors appear to provide a balanced report of the research and the issues involved - and they're experts and the magazine grooms fair and accurate information.