what are the symptoms of autisim in teenagers?

Answer 1

Autism can be diagnosed at ANY age. I had a friend whose cousin was diagnosed after age 30.

Most of the problem would be in social interaction. If a teen has a hard time reading body language or can't seem to say things the right way to get the response he wants, that can be a sign. Another sign would be talking too loud or too soft. Autistic people have trouble knowing whether the other person can hear them. Autistic teens usually have a hard time looking into someones eyes while talking. They generally look at someones lips while that other person is talking. The teen wouldn't be able to pick up on social cues, like whether a girl is flirting or not. They are generally "loners" -- not necessarily by choice, but because they don't know how to become friends with someone. Another sign is incredibly sensitive senses that are easily overwhelmed - like not being able to tolerate the sound of a school bell or bass in a car stereo. Unusually sensitive to light or touch is also common. So is picky eating and obsessive behavior. The teen would want to talk about and learn about one thing in particular. For my son, it was men's ties, rocks, inventors, chemistry and many modes of transportation.

A great book you might want to read is Asperger's Syndrome by Tony Attwood. He's considered USA's top doctor when it comes to diagnosing and treating Autism. Tempil Grandin, a very famous woman with Autism co-authored a book about Autism Spectrum Disorders.
Some fiction that might be pertinent is The Curious Incident of the Dog in the Night-time by Mark Haddon. I haven't read A Spot of Bother, and I can't find the synopsis online. It might also have an Autistic character. The Speed of Dark has an Autistic man as the main character. It was written by Elizabeth Moon and is very well-written.
Movies of interest might be Rain Man, with Dustin Hoffman and Tom Cruise. I wouldn't let your possible opinion of Tom Cruise get in the way. It's a good movie even though he's in it. Another movie, Mercury Rising, with Bruce Willis, is well done. The Autistic character is a young boy.
You might also want to read about some people who have Autism. Born on a Blue Day by Daniel Tammet is written by a man who was formerly an Autistic Savant. And the book 7 kinds of Smart by Thomas Armstrong mentions Tempil Grandin (the lady I mentioned above as a co-author).

These are links that talk about Autism that you might want to view:
http://www.mayoclinic.com/health/autism/DS00348/DSECTION=2
http://www.wrongdiagnosis.com/a/autism/signs.htm
http://autism.about.com/od/transitioncollegejobs/Teens_and_Autism.htm teens with autism and the unique problems parents have when they have an Autistic teen

This should at least get you started on knowing what Autism is and the very many ways it has been represented in the media. A good site if you want to join a community on line is:
http://groups.msn.com/TheAutismHomePage/parentsupportgroups.msnw for parents and
http://www.wrongplanet.net/ for people who have Autism.

Answer 2

lack of social skills is the best sign. not looking a person in the eye when they talk with them. being an expert on one subject, but clueless about others they should know about. they should have been diagnosed as a toddler, though.

Answer 3

Autism is diagnosed in childhood. You don't suddenly have it as a teen or adult.

Here are the facts:

http://www.ninds.nih.gov/disorders/autism/detail_autism.htm