Thursday, July 2, 2015
ADD vs. ADHD
With the known differences between ADD and ADHD, why are they treated with the same medication? Some of the differences are extremely opposite. Not only in medical terms but also with day to day experiences. As a child I was diagnosed with ADD and my 2 brothers where ADHD. The differences in how we acted morally, learning difficulties, and depression just to name a few, were totally opposite. Like night and day. As an adult both brothers have "out grown" their ADHD but my ADD is still here and worse than ever without medication.
You have highlighted a diagnostic problem that ADHD experts are struggling with, but you used obsolete terminology. ADD is not currently a separate diagnosis, but is now a subtype of ADHD. ADHD is diagnosed as predominantly inattentive (which you refer to as ADD), predominantly hyperactive-impulsive, or combined type. It sounds like your two brothers had one of the latter two types. The hyperactive-impulsive symptoms are often outgrown, but the inattentive symptoms remain a problem for many. If you compare notes with your brothers, you may find that that have the same inattention problems as you even though their hyperactive-impulsive symptoms are gone.
Whether the predominantly inattentive type is really a subtype of ADHD is currently under intense study. Group data from drug clinical trials suggest that the inattentive type responds similarly to medication as the combined type. However, a subgroup of the inattentive type has been identified that is described as having a "sluggish cognitive tempo", actually being hypoactive rather than hyperactive, with learning disorders, and many experts suspect that this subgroup is fundamentally different from all other ADHD, including many of the inattentive type. It is this subgroup that may contribute to the occasional finding of a difference by type. For example, we recently reported a significant interaction of type by treatment in response to acetyl-l-carnitine (ALC) vs. placebo: the inattentive type responded better to active ALC than to placebo, while the combined type responded as well to placebo as to active ALC. However, this could be a chance finding and needs replication before accepting it.
L Eugene Arnold, MD, MEd
Professor Emeritus of Psychiatry
College of Medicine
The Ohio State University