Aspergers VS. Nonverbal Learning Disorder - Similarities and Differences

When my son received his diagnosis of Nonverbal Learning Disorder (NLD) he also scored as "high likely" for Asperger's Syndrome (AS). I found this very confusing for a long time and sometimes felt like the correct diagnosis should have been AS. Other times I felt that NLD was in fact the correct diagnosis. Still other times I wondered if maybe he had both.

When two disorders look very much alike it can be very hard to be sure the correct diagnosis is made. Nonverbal Learning Disorder and Asperger"s Syndrome are two such disorders. Lets take a look at some of characteristics of each. I have placed the following symbol next to the characteristics in both lists that fit my son.

Nonverbal Learning Disorder (adapted from this article)

• Toddlers may be unable to put puzzles or together or perform other tasks that require similar skills *
  
• Child dislikes construction toys * (As he has gotten older he has learned to enjoy construction toys but used his own imagination to create things. Following a sequence of written instructions is very difficult)
  
• Children are clumsy, poorly coordinated and easily lose their balance *
  
• Learning to ride a bicycle is extremely difficult
• Fine motor skills are difficult to learn, such as learning to tie shoelaces*
• Child excels at memorization tasks and uses language to talk through tasks which rely on kinesthetic memory. *
  
• Child presents with clinical signs of anxiety, depression and attentional problems*
  
• Problems with interpersonal functioning*
• Difficulty reading body language of others*
• Difficulty discerning humor and misinterprets teasing*
• Unable to understand symbolic language, are very "concrete" in speech interpretation*
• Failure to observe "personal space"*
• Difficulty remembering how to get from room to room,place to place, etc., may become easily lost*

Asperger's Syndrome (adapted from this article)

• problems with social interaction, particularly reciprocating and empathizing with the feelings of others*
• difficulties with nonverbal communication, such as facial expressions*
• peculiar speech habits that include repeated words or phrases and a flat emotionless vocal tone
• an apparent lack of common sense*
• a fascination with obscure or limited subjects, often to the exclusion of other subjects* (sometimes)
  
• clumsy and awkward physical movements*
• odd or eccentric behaviors - hand wringing, finger flapping, swaying, etc.* (sometimes - may be due to anxiety)
  

Then there are those who propose the theory that these two disorders may actually be the same thing or at the very least overlap. There is a very interesting article here that does a great job of discussing this theory. Could it be that what are currently considered to be two separate disorders are two different places on a continuum? And if they are, would it make a difference in services provided and in ways of supporting the individual?

I don't have the answers to these questions but I definitely feel they are worth pursuing, looking at closely and discussing with professionals and parents. There may be a danger in over categorizing and missing the bigger picture.

I would love to hear from other parents who have had any experience with these issues.