ADD: How Is It Different From ADHD? Attention Deficit Disorder or ADD is a very complicated, and time and again misinterpreted, disorder. I ts beginning is physiological, but it can have a multitude of consequences that come alongside with it. That apart, what is the differentiation between ADHD and ADD? ADHD is the abbreviated form of Attention Deficit Hyperactive Disorder, its major indications being noticeable hyperactivity and impulsivity. These are the indications that are noticeable to the purposeful onlooker. ADD stands for Attention Deficit Disorder with the major indications being lack of concentration. Now a lot of other things can come alongside with both of these subtypes of ADHD, but those are the distinctive characteristics of both.