10. What is the difference between 'ADD' and 'ADHD'?
In the past 'ADD' referred to children without hyperactivity; 'ADHD' to those with hyperactivity.
The current terminology, used internationally since 1994, refers to all forms of the condition by the umbrella term 'ADHD' (Attention-Deficit/Hyperactivity Disorder). -TOP-
This current terminology recognizes 3 sub-types of ADHD: the inattentive type, the combined type, and the hyperactive-impulsive type. The 'inattentive type' corresponds to 'ADD' in the old terminology.
Using the current terminology, it is possible to have ADHD and not to be hyperactive.