ADD and ADHD are disorders that make it difficult to control behavior and learn at a normal pace from a young age into adulthood. They are caused by differences in brain structure and chemical levels that affect attention, self-control, and behavior. Studies have shown that children with ADHD reach peak brain development three years later than children without ADHD, though both have healthy development overall. Treatment options aim to reduce symptoms through stimulant medications, behavioral therapies, and support groups.