Until today I had never heard of the shortened term "aspie" to refer to someone with Asperger syndrome. While the term strikes me as derogatory and belittling, I'm not a native speaker and obviously have no experience with its usage.
An online search seems to provide no conclusive evidence that it's an offensive term. I've found a few statements from parents of children with the syndrome or mental health workers who claim to use the term. Some say that it can be offensive depending on tone and usage. Yet others say that it shouldn't ever be used.
Is the term "aspie" innately derogatory?
Is there a good chance that some people might take offence at its usage and should I therefore avoid using it?
Best Answer
To directly answer the question: the word is not inherently derogatory (meaning it does not, in and of itself, carry any negative connotations).
Here is the rationale:
That said, if a specific person doesn't want to be called "aspie" (for whatever reason), don't call them that. It's a matter of honoring their wish.
I don't like the diminutive version of my name (and often ask people not to use it), but it does not follow that the diminutive version of my name is somehow derogatory. The simple fact is it's merely diminutive or informal.
Some sources and further reading:
(Wikipedia)
(Oxford American Dictionary)
(Both snippets taken from Urban Dictionary definitions.)
In addition, consider the definition and examples from Oxford Dictionaries:
These examples are obviously not pejorative terms. Judging by their style, they appear to come from some medical research papers, which wouldn't use derogatory terms.
Here is another example from a Kathy J. Marshack, Ph.D., who is a psychiatrist (apparently dealing with the issue on a regular basis):
Two observations:
(A) It would be inconceivable for a person of the medical profession to routinely use a pejorative term in a publication about patients.
(B) In the context of the article, she repeatedly uses "aspie" as a neutral, informal term (and also as a convenient adjective), not as a derogatory term in any way, shape, or form. (My guess is, the adjectival form is here to stay, as the alternative is often unwieldy.)
NOTE: The answer is provided based on my research and experience. To err is human, so if you have evidence to the contrary (dictionary definitions, derogatory usage, etc.), please let me know.