Is it true that autism/Asperger's is more common in boys than in girls?

[bluestateguy]

And if so, I wonder why. I can only think of one or two times that I ever met a girl with autism or Asperger's.

And how about ADHD? Seriously, educate me here. Is ADHD more common in boys than girls?

And then of course when it comes to behavioral problems in schools, boys are a far bigger problem than girls, especially when it comes to violent behavior.

[existentialist]

1. Just a guess, but

I'm thinking it's probably x chromosome related.

A lot of genetic illnesses that are x chromosome related are more common in men than women because women have two chances to get a healthy gene, and men only one. Examples include:

color blindness
hemophilia
some kinds of intelligence, including perhaps some autism related kinds of intelligence

Please keep in mind that I know just enough about this to be dangerous, but I'm sure someone here can correct me if necessary.

[pitohui]

2. it is true for autism/asperger's

i do not know why, however, it did not stop me as a girl being mis-dx'd w. autism

know nothing about adhd really so won't comment on that

[aquart]

4. Girls aren't so much into the hyperactivity.

Just ADD.

Don't know the cause but I'm going with genetic. My sister has the fun side effect: synesthesia. Both she and my mom describe pain in terms of color. And when I phoned my sister and asked her the color of the letter "O," she said "White" without pausing to consider. "White" is the most common answer to that question if you have synesthesia. Which she had never heard of.

[Odin2005]

3. High-Functionuing Autism is more common in males and...

...Low-Functioning Autism is more common in females.

Oh and please don't use "boys" and "girls", it implies us adult autistics don't exist.

[marions ghost]

5. I think ADD is

equally common in both sexes--but it manifests differently in the sexes. This article explains it pretty well. I have both girls and boys with ADD in my family. The boys tend to be more hyper (ADHD) while the girls are distractable, time-challenged, & have difficulty focusing. Both can be prone to substance abuse. It's important to identify it in girls--often missed. Someday this constellation of characteristics will be called something else. It is not attention deficit, it is attention inconsistency. Often there is hyperfocus, obsessive focus.

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"There are several different types of ADDmany people think Attention Deficit Disorder (ADD) is a boy's disease. It is commonly believed that it occurs at least twice as often in boys as in girls. Although it is true that boys are more often diagnosed, the rates are actually about the same in both genders. Boys more often have the variety called Attention Deficit/Hyperactivity Disorder (ADHD) - and that's what tends to get their problem noticed.

Parents, teachers, and even health professionals tend to picture the classic case of ADD as a boy with a lot of hyperactivity. The average girl with ADD acts differently. In girls, the disorganization and distraction results in lack of activity--they are just too confused to get things started, and instead are often described as daydreamers.

This is in stark contrast to the boys. Boys' distractibility is expressed as impulsivity--a flurry of activity. While both genders have trouble learning the nuances of social interactions, the results for each are different. Girls end up shy and withdrawn - they don't like the negative reactions they get when they don't clue in to the nuances. Boys on the other hand are more likely to proceed with social behavior that is considered inappropriate. While they are bewildered when they get negative reactions, they continue." (more at link)

http://www.science20.com/science_motherhood/girls_add_why_it_so_often_missed