If you live with ADHD, you’ll be happy to know that you’re not “brain-damaged” and you don’t have a “disease of moral control.” But that might have been your diagnosis 50 or 100 years ago.

Today, the therapeutic community defines Attention-Deficit/Hyperactivity Disorder (ADHD) as a neurobiological syndrome with genetic and environmental components. There are three core traits, which may present in various combinations depending on the individual:

• Inattention (distractibility)
• Hyperactivity (physical and/or cognitive restlessness)
• Impulsivity

The timeline below highlights key developments in the history of this definition. As you can see, our understanding has come a long way. However, it’s clear that the collection of characteristics and behaviors we now recognize as ADHD has been observed for thousands of years. ADHD is not, as some have argued, a new phenomenon that was caused by video games or trumped up to sell pills.