What You Need to Know at Every Stage of Life If you've ever wondered whether you or someone you love might have ADHD, you're not alone. Attention-Deficit/Hyperactivity Disorder is one of the most common neurodevelopmental conditions in the world — and one of the most misunderstood. For many people, receiving a formal diagnosis is a life-changing moment that finally gives a name to years of struggle. For others, the idea of seeking a diagnosis feels daunting or unnecessary. So