Last Thursday, the question of whether there was any sort of overlap between the various specific learning disabilities/differences (SLD) was raised in one of my favorite twitter chats.
I knew at the time that there was a lot of symptom overlap, and many people are identified with combinations of SLD, but I didn’t have any resources at hand. I spent this morning looking up symptoms of dyslexia, dysgraphia, dyscalculia and dyspraxia.
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There are probably more SLDs out there, and not all governmental entities use these names, but those are the four I hear the most about. I chose that particular set of symptoms, because they seem to be the most common. It’s worth noting that I couldn’t find much about dyspraxia, so there may be more to it than is indicated on that chart. Not all people who carry these labels manifest every symptom, nor do they show up in quite the same way.
Fine and gross motor control is included in that first column. I was a bit hesitant to mark that category for dyslexia and dyscalculia, because dysgraphia and dyspraxia are heavily under-identified. They could be why I found so many stories of dyslexic and dyscalculic kids having such a hard time with fine motor skills. Since I don’t know missed diagnosis is at fault, and those problems are so prevalent, I ticked the box.
Comorbidity, or presence of more than one SLD in the same person, is pretty common, too.
According to this article from Parents Canada, about 2/3 of people with dyscalculia also have dyslexia. According to Your Amazing Brain, 40% of dyslexics also have dyscalculia, though I’ve seen that number get closer to 50% in some places.
Because dysgraphia and dyspraxia are still so poorly researched, I couldn’t find concrete figures for overlap between those SLDs and the others. In fact, experts are still unsure of how many people have these differences. However, in almost every resource I came across, it was stressed that dysgraphia is common in the dyslexic population. Unfortunately, dysgraphia and dyspraxia are both poorly understood, perhaps more so than dyscalculia, and certainly dyslexia.
Because diagnosis isn’t always accurate, it’s hard to put a huge amount of stock in percentages and figures. What’s out there now, however, shows there are some striking similarities between specific learning disabilities, and often a large overlap.
This research has also demonstrated just how much more study needs to be done, and awareness spread.
That’s part of why I like the chat this question originally came up in. If you’d like to join us, the tag is #DDChat, and it takes place every Thursday on twitter at 2 PM Central Standard Time. Here’s a handy dandy graphic from Dyslexia and Me‘s page with what time it takes place in other time zones:
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