Are Adult and Childhood ADHD Different Conditions?

 ADHD in the News 2016-08-18

Diagnosing an adult with attention-deficit/hyperactivity disorder (ADHD) requires at least five symptoms of inattention and/or hyperactivity and impulsivity, per the American Psychiatric Association’s Diagnostic and Statistical Manual of Mental Disorders (DSM-5)...What if an adult has indications of ADHD, but didn’t as a child? Could adult and childhood ADHD be two distinct conditions?