When I run my ADHD group, I start off with an orientation that includes sharing how complex ADHD really is. And one of the things that surprises most group members is hearing that ADHD is actually seen as multiple conditions. And I’m talking about something bigger than whether one’s diagnosed as having a “presentation” of ADHD as primarily inattentive, primarily hyperactive or a mix of both.
As Joel Nigg at OHSU puts it, ADHD appears to be an “umbrella diagnosis,” such as cancer once was (see here). Cancer was thought to be a single disease, and we now know there are various types of cancer.
Researchers are currently trying to identify the various conditions found under the umbrella of “ADHD.” Each may have different genes, environmental causes, and clinical outcomes. They likely have different brain signatures (see Understanding ADHD for more on brain differences).
And they may have different optimal interventions.
This complicates research findings that include participants only because they share a diagnosis of ADHD. It might be like trying to understand cancer by averaging results across participants with skin cancer and liver cancer. Or perhaps it’s more analogous to averaging results across participants with different forms of skin cancer. It’s unclear.
Once the fog clears, I’m excited to know what we’ll learn about the different conditions all now diagnosed as simply ADHD (with three “presentations”).