A new study shows that medication frequently used to treat attention-deficit hyperactivity disorder, or ADHD, could be linked to lower bone density in children. Children taking such common stimulants as Ritalin, Concerta, and Adderall were found to have a lower bone density than children that had not been on these medications, researchers found. According to a lead physician on the study, lower bone density has serious health defects later in life, including a higher risk of fractures and potential osteoporosis. Over 6,000 children between the ages of 8 and 20 were examined in the study, with children who had been on ADHD medication showing about 5 less bone density than their peers.