the differences between nld and asd are minute but not negligible. i know this since i have known three people with nld, one of whom is related to me.
the major difference between the 2 is that nld has a specific neurological profile and brain studies of people with nld show that their right hemisphere is less active than their left hemisphere, while brain studies of people with a.s. or autism do not show any consistent profiles with each other. it is possible the 2 disorders are related since they both affect brain connectivity (white matter), which is found more in the right brain and the connections between the 2 hemispheres.
many mathematicians and engineers are thougth to have a.s., yet they most likely would not fit the nld label. someone with nld might be very good at mental calculations, yet struggle with math concepts. the opposite is true for me because of working memory.
i think another major difference between the two is how someone with nld may exhibit most of the symptoms and still have near normal social skills, which would improve if their processing of non verbal cues was better. someone with asd may learn to read body language over time if they are good at analyzing visual details, but still be poor at perspective taking. when i was about 9, i had a friend with nld, and we did not have much in common. she was more talkative than me and more interested in socializing, while i used to pay more attention to objects than people.
people with asd's often look conspicuously odd because of their facial expressions, gestures, and postures, yet people with nld give a normal first impression, and it is impossible to tell that anything is wrong with them until you have known them for a long time.
both disorders cause severe sensory issues and i have no idea why sensory integration dysfunction is not mentioned in the dsm descriptions of asd's. Yet while the sensory profile of those with nld is relatively consistent, (better auditory processing than tactile or visual or motor skills) the sensory profiles of autistic people are extremely inconsistent. for example, it used to be common for me to excel at a certain visual task one day and fail the same task another day. my performance on tasks of visual or tactile processing or motor skills range anywhere from the gifted range to the mildly impaired range and sometimes the tasks where i had low scores were only minutely different from those in which i had high scores. moreover, people with nld show a significant difference between verbal and nonverbal scores, while people with high functioning asd's have some perceptual skills which are as high, or higher, than their verbal skills.
it is also noteworthy that those with nld do not have any auditory processing problems, while those with asd often do, because they cannot separate what is relevant from background noise. people with nld also rely on words to make sense of the world, while some people on the spectrum, like me, may sometimes find certain word concepts to be arbitrary and culturally biased. people with nvld also verbalise all of their thoughts, usually in complete, grammatical sentences, while many people with autism take longer to verbalise their thoughts.
the similarities between asd and nld go beyond sensory issues and social skills, yet one could question whether their thought processes are similar or not. both groups of people interpret language literally, yet it seems that people with nld are a bit less literal than people with asd, since theory of mind is supposed to be preserved in individuals with nld. it seems as if once a word meaning is encoded in their rote memories, they cannot let go of it. literal thinking in those with asd is caused by both inflexibility and lack of perspective. both groups of people also have "weak central coherence". Yet the issues in coherence in people with nld is thought to result from being better at sequential thinking than simultaneous processing and also from not being able to visualize how information is linked into complex idea maps. this is different from the intense hyperfocusing seen in individuals with asd.
i think that one reason why nld and a.s. are confused with each other is that before nld was known by psychologists, those with nld were misdiagnosed as having a.s. it is also possible that those with mild a.s. or atypical autism that is mild, are thought to have nld, because they seem to be too socially functional to fit any other diagnosis. since a.s. is 9 times more common in males than females, girls and women with a.s. are probably misdiagnosed as having nld.
06 Jun 2009, 3:25 pm
