It was originally called ADD. Then they forced the H in there for hyperactivity. And now they say there is non-hyperactive ADHD, but... they don't call it ADD.

So the first rule of getting attention for your paper is to re-define common terms...

The word you are looking for is Inattentive - when diagnosed they should state whether the diagnosis presents as Predominantly Inattentive, Predominantly Hyperactive/Impulsive, or Combination.

The origin of ADD as a diagnosis is the DSM-III (1980), which calls it "attention-deficit disorder with or without hyperactivity". Do better.