I just read an interesting article (http://www.ncbi.nlm.nih.gov/pubmed/18726986?ordinalpos=7&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsP anel.Pubmed_DefaultReportPanel.Pubmed_RVDocSum) about how certain ADHD genes (http://www.ncbi.nlm.nih.gov/pubmed/18726986?ordinalpos=7&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsP anel.Pubmed_DefaultReportPanel.Pubmed_RVDocSum) can actually cause completely different symptoms in boys and girls. It mentions that some of the differences might be to a specific sex-linked gene associated with ADHD called monoamine oxidase A (MAOA), which is found on the X-chromosome. Males, who lack the 2nd X-chromosome lack something to offset it, so this may be a notable reason why ADHD is more common in males.

There are multiple genetic forms in this area (i.e. there are a number of different types or "flavors" of this genetic region, but there was one genetic form of particular interest. Males with this specific gene type had poor motor control issues, while females with this specific gene type showed an improved form of working memory (dealing in particular with visual and spatial information). So, in other words, a specific form of a genetic region tied to ADHD resulted in an increase in something good in girls, but something bad in boys.

I really think this lends credibility to the idea that the root causes of ADHD and so-called "ADHD genes" need to be viewed differently between boys and girls, because clearly, the net effects can be entirely different between genders.

I also wonder if these gender-different responses with regards to this "ADHD gene" may have an important effect on certain drugs that target Monoamine Oxidase (like MAOi's such as Selegiline). While many of these types of drugs are older forms of antidepressants, some, like Selegiline can be used to treat ADHD. If this is the case, and the gene MAOA is sex-linked, do you think the gender of the patient may be a much more significant factor in determining the overall effectiveness of the drug? Your thoughts?

I just read an interesting article (http://www.ncbi.nlm.nih.gov/pubmed/18726986?ordinalpos=7&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsP anel.Pubmed_DefaultReportPanel.Pubmed_RVDocSum) about how certain ADHD genes (http://www.ncbi.nlm.nih.gov/pubmed/18726986?ordinalpos=7&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsP anel.Pubmed_DefaultReportPanel.Pubmed_RVDocSum) can actually cause completely different symptoms in boys and girls. It mentions that some of the differences might be to a specific sex-linked gene associated with ADHD called monoamine oxidase A (MAOA), which is found on the X-chromosome. Males, who lack the 2nd X-chromosome lack something to offset it, so this may be a notable reason why ADHD is more common in males.

There are multiple genetic forms in this area (i.e. there are a number of different types or "flavors" of this genetic region, but there was one genetic form of particular interest. Males with this specific gene type had poor motor control issues, while females with this specific gene type showed an improved form of working memory (dealing in particular with visual and spatial information). So, in other words, a specific form of a genetic region tied to ADHD resulted in an increase in something good in girls, but something bad in boys.

I really think this lends credibility to the idea that the root causes of ADHD and so-called "ADHD genes" need to be viewed differently between boys and girls, because clearly, the net effects can be entirely different between genders.

Very good posts.
I do not keep up too much with this area of research but you are looking at where the action is.

I do know through reading and experience that the expression of ADHD is often quite different in girls than in boys. The better diagnostic behavior surveys (in my opinion) have different norms for boys and girls as many girls will be missed if you norm on the general population.


Dizfriz

Just to add to the discussion a bit. We often think of ADD/ADHD as more Westernized disorders, but what about the rest of the world? There was very interesting study (http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1626473) done on multi-ethnic South African children to test fine motor skills and their association with ADHD for differences based on gender, age, dominant hand and ADHD subtype. Results were compared to a control group of children without ADHD. Here is a link to the whole article (http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1626473). It's not overly technical and has some awesom charts that compare results across age, gender, hand dominance and subtype. If you have a few minutes, I highly recommend checking it out (http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1626473). If not, here are a few key points from the article:

1. Three different tests were performed: the Grooved Pegboard Test (timing how long it takes an individual to place appropriate pegs in corresponding holes), the Finger Tapping Test ( recording the number of times an individual can tap their index finger in 10 seconds ), and the Maze Coordination Test (moving a pen through a narrow maze while trying not to touch the sides)

2. The children came from a variety of ages and 7 different ethnic groups.

3. Age was a significant factor in fine motor skills performance across both genders and all subtypes.

4. Individuals with the Combined subtype of ADHD showed the highest levels of impairment in fine motor skills for the younger children. This effect was signifiantly less pronounced in older ADHD children. There was minimal difference between gender-based performance for this subtype.

5. There was little difference in fine motor skill performance based on the tests administered between the dominant and non-dominant hand.

6. ADHD girls performed worse than ADHD boys for the maze and peg board test, but were even for the finger-tapping test. This suggests that ADHD girls, while typically even with ADHD boys in terms of speed, are noticeably worse when the speed is combined with accuracy for manual dexterity. This goes along with general findings from several other studies that indicate that although ADHD is much more common in boys , the overall level of impairment associated with the disorder is often more pronounced in girls.

There are multiple genetic forms in this area (i.e. there are a number of different types or "flavors" of this genetic region, but there was one genetic form of particular interest. Males with this specific gene type had poor motor control issues, while females with this specific gene type showed an improved form of working memory (dealing in particular with visual and spatial information). So, in other words, a specific form of a genetic region tied to ADHD resulted in an increase in something good in girls, but something bad in boys.


That's pretty cool. I wonder how that ties in with the (what I'm lead to believe is a) relatively high intelligence of ADHD patients.