A new meta-analysis published in Clinical Psychology Review is questioning some of the assumptions the DSM makes about hyperactivity, especially the idea that there’s a clear distinction between ADHD’s inattentive and hyperactive subtypes.
Instead, the paper suggests an alternate way of looking at things: ADHD could reflect a general disposition toward being hyperactive in certain environments, and hyperactivity could be a coping mechanism for dealing with specific situations rather than an immutable characteristic of the disorder.
To learn more about the role of hyperactivity in ADHD, the researchers analyzed 63 peer-reviewed studies comparing levels of motor activity between people with and without ADHD. As expected, the people with ADHD were more active overall.
When the authors dug a little deeper, though, things got interesting.
First, they looked at how study participants’ ages and ADHD subtypes influenced hyperactivity. Conventional ADHD wisdom suggests that children are more hyperactive than adults and that, obviously, people with hyperactive-impulsive ADHD are more hyperactive than people with inattentive ADHD.
Crunching the actual data, however, the researchers ended up with results that flew in the face of these assumptions:
- Children and adults with ADHD were equally hyperactive.
- People with inattentive ADHD were as hyperactive as people with hyperactive-impulsive ADHD.
When the researchers looked more closely, it turned out that rather than being an innate, constant trait of particular ADHD subgroups, the difference in activity levels between people with and without ADHD tended to become more pronounced under certain environmental conditions.
Specifically, tasks that were cognitively demanding and that relied more on executive functioning generally exacerbated hyperactivity in people with ADHD. Environments that were low in stimulation also increased the gap in activity levels between people with and without ADHD.
These findings are consistent with the idea that hyperactivity is more of a coping mechanism than a core symptom of ADHD – that people with ADHD engage in behaviors like fidgeting as a way of dealing with other underlying symptoms like inattention.
What they aren’t as consistent with is the DSM’s delineation of inattention and hyperactivity as two basic categories of symptoms. Instead, it’s possible that inattention and hyperactivity are more interlinked and that hyperactivity is a way of dealing with certain environmental demands.
This study caught my eye because to me, the line between inattentive and hyperactive symptoms has always seemed a little artificial. The two feel interlinked, and my experience isn’t that there’s a place where one stops and the other begins. So I can see how one way of looking at it could be that that hyperactivity is a response to environments that put more of a burden on inattentive symptoms.
In fact, I’m not going to say “I told you so” or anything, but here’s what I wrote about inattention and hyperactivity a couple months ago:
Since I have ADHD, I tend towards thinking about ADHD in terms of what it feels like from the inside rather than how it looks to a third-party observer, which is why the distinction between inattention and hyperactivity has never made much sense to me. Being unable to sit still and having trouble concentrating might look like different behaviors from the outside, but internally, they feel pretty much the same.
Of course, one meta-analysis isn’t enough to conclude that we should tear up the DSM and stop talking about ADHD subtypes, but I hope more studies look at this question in the future rather than taking the division between inattentive and hyperactive subtypes at face value – this seems like a line of research that could lead to a better understanding of what ADHD is and how people with ADHD can live better lives.
What d’you think? Do you have hyperactive symptoms? How do you experience the relationship between inattention and hyperactivity?