Figuring out the best way to diagnose ADHD is an ongoing project that researchers and clinicians both grapple with.
The current system, using the diagnostic handbook the DSM, lists nine inattentive and nine hyperactive-impulsive symptoms of ADHD. To qualify for a diagnosis of ADHD, you need to display six or more symptoms in at least one of those categories.
In practice, that means there are a lot of different symptom profiles that can lead to a diagnosis. In fact, if you do the math, you end up with 116,200 possible ways of diagnosing ADHD under the DSM guidelines, according to a comment article recently published in Lancet Child & Adolescent Health.
Another way to think about it is that if you pick two ADHDers at random, they’re almost guaranteed not to have some symptoms in common. There are a lot of different ways to have ADHD, as it’s defined in the DSM, so from that perspective it’s not so surprising that different people experience the effects of ADHD differently.
At the same time, one of the theories behind the DSM is that various symptoms are on some level expressions of the same underlying situation, either inattention or hyperactivity-impulsivity (which are themselves related).
Take two examples of inattentive symptoms: being forgetful in daily activities and making “careless” mistakes. These are distinct behaviors, but they’re not entirely unrelated since inattention would seem to factor into both of them.
Or another pair of examples: having trouble sustaining attention and being distracted by extraneous stimuli. These might be even more closely related. They aren’t exactly the same – after all, it’s possible to have trouble concentrating without necessarily being distracted by something. However, someone who easily gets distracted by things going on around them is also probably going to be someone who has trouble sustaining focus in general.
So in that sense, it might be overstating the case a little to say there are 116,200 ways of having ADHD, even if there are technically that many ways of meeting the diagnostic criteria.
At the same time, as the authors of the Lancet article point out, there are even more potential differences between ADHDers that the DSM doesn’t take into account. These include things like comorbid conditions, subtypes of ADHD that might arise from different neurobiological causes, or subtypes that might have different profiles in terms of symptoms that aren’t listed in the DSM.
The takeaway, then, is probably that ADHDers are similar but also different. On some level, we have something in common in terms of inattention and impulsivity, but the specific behaviors in which that common something expresses itself can vary significantly from one ADHDer to the next.
Image: Flickr/Ruud van Eck