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> Oh then there is the fact that there are large structural brain differences. Are these structural differences used in diagnosis?

com2kid 13y ago
> Are these structural differences used in diagnosis? Unfortunately testing costs money, I've rarely to never heard of it being used, but my sole experience is in helping people on ADHD support forums.
- dalke 13y ago
  When you say it is a "fact that there are large structural brain differences", which differences did you mean? I may be focusing on the wrong thing. What I've found (brain size) doesn't have a clear enough difference to be used as part of diagnosis. For example, http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2859218/ http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2859218/ notes that head circumference and cross-sectional MRI measurements of brain size show that children diagnosed with autism have (on average) a larger brain size. However, looking at the charts (for a head circumference chart, see http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3869044/ http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3869044/ ), while the data may be statistically significant, there's no clear separation between those diagnosed with autism and those with no indication of autism. Many of those with autism have a size smaller than the average of those without, and many of those without autism have a size larger than those with. This means that head size or simple cross-sectional MRIs can't be used as a reliable diagnostic test. Which structural differences where you meaning?
  - com2kid 13y ago
    Not the entire brain, just the portions that deal with self control! This is actually where the "Hyperactive" part of ADHD comes from, normally the parts of the brain that control motor skills and the parts that allow for self control grow in tandem, for children with ADHD, their motor skills outpace their self control. Their executive functioning eventually catches up, thus the myth of "children grow out of ADHD" came to be, since the "H" disappears, unfortunately the rest of the problems remain. http://www.sciencedaily.com/releases/2012/07/120730094822.htm http://www.sciencedaily.com/releases/2012/07/120730094822.ht... http://www.nami.org/Template.cfm?Section=ADHD&Template=/ContentManagement/ContentDisplay.cfm&ContentID=106828 http://www.nami.org/Template.cfm?Section=ADHD&Template=/Cont...
    - dalke 13y ago
      Thank you for the pointers. They appear to be about the same research program. They share the same author, Philip Shaw. From the first "We measured the thickness of the cortex across thousands of points in the brain in .. (466) children - half of whom had ADHD and half of whom did not" and from the second "They recruited 234 children with ADHD and 231 typically developing children ... they were able to map the trajectories of surface area development at over 80,000 points across the brain." Even though they appear to be different efforts (the number of children involved are different and the years are different), there might still be some spurious correlations solely because the same people, with the same expectations and analysis technique, are involved. Unfortunately, I am unable to read the primary literature. The first links to a paywalled journal article ($31.50), the second doesn't have a journal citation. I found http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3342014/ http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3342014/ by the same author, and published a couple of months after the article in the first link. Unfortunately, which it says there are distinguishable features, along with two reference comparisons, it doesn't give enough information to judge if those differences are truly diagnostic. I did find http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3440402/ http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3440402/ which comments "The ADHD diagnosis rests only on these symptoms because no biological markers (e.g. genetic tests, brain imaging) have been validated [11]", but that reference [11] is from 2006, and older than the two links you gave. A 2007 metaanalysis (so again, older than the two references you gave) at http://www.ncbi.nlm.nih.gov/pubmed/16950217 http://www.ncbi.nlm.nih.gov/pubmed/16950217 points out that at that time "Although there are many structural neuroimaging studies of attention-deficit/hyperactivity disorder (ADHD) in children, there are inconsistencies across studies and no consensus regarding which brain regions show the most robust area or volumetric reductions relative to control subjects." To highlight the intent behind those last two previous paragraph, they are saying that there are many studies like the ones you pointed out, which show a correlation between some physical measurement and ADHD. Unfortunately, they don't seem to be consistent. Because of the well-known publication bias problem, it's likely that false positives are over-reported. It takes additional followup work to determine if those signals are really true, and if they are distinguishable enough to be used diagnostically. This all tells me that there is no "large structural brain difference", and especially not one which has been validated as a diagnostic tool. There might be a small structural brain difference, but again, I find no evidence that identification of this difference is available as a diagnostic tool at all, even if the price were disregarded. Again, I might be focusing on the wrong thing, but perhaps you may be misinformed? If most of your research is through the popular literature, then my earlier reference to http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3440402/ http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3440402/ ("Why Most Biomedical Findings Echoed by Newspapers Turn Out to be False: The Case of Attention Deficit Hyperactivity Disorder") may be useful: > Because newspapers preferentially echo initial ADHD findings appearing in prominent journals, they report on uncertain findings that are often refuted or attenuated by subsequent studies. If this media reporting bias generalizes to health sciences, it represents a major cause of distortion in health science communication.

com2kid 13y ago

> Are these structural differences used in diagnosis? Unfortunately testing costs money, I've rarely to never heard of it being used, but my sole experience is in helping people on ADHD support forums.

dalke 13y ago
When you say it is a "fact that there are large structural brain differences", which differences did you mean? I may be focusing on the wrong thing. What I've found (brain size) doesn't have a clear enough difference to be used as part of diagnosis. For example, http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2859218/ http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2859218/ notes that head circumference and cross-sectional MRI measurements of brain size show that children diagnosed with autism have (on average) a larger brain size. However, looking at the charts (for a head circumference chart, see http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3869044/ http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3869044/ ), while the data may be statistically significant, there's no clear separation between those diagnosed with autism and those with no indication of autism. Many of those with autism have a size smaller than the average of those without, and many of those without autism have a size larger than those with. This means that head size or simple cross-sectional MRIs can't be used as a reliable diagnostic test. Which structural differences where you meaning?
- com2kid 13y ago
  Not the entire brain, just the portions that deal with self control! This is actually where the "Hyperactive" part of ADHD comes from, normally the parts of the brain that control motor skills and the parts that allow for self control grow in tandem, for children with ADHD, their motor skills outpace their self control. Their executive functioning eventually catches up, thus the myth of "children grow out of ADHD" came to be, since the "H" disappears, unfortunately the rest of the problems remain. http://www.sciencedaily.com/releases/2012/07/120730094822.htm http://www.sciencedaily.com/releases/2012/07/120730094822.ht... http://www.nami.org/Template.cfm?Section=ADHD&Template=/ContentManagement/ContentDisplay.cfm&ContentID=106828 http://www.nami.org/Template.cfm?Section=ADHD&Template=/Cont...
  - dalke 13y ago
    Thank you for the pointers. They appear to be about the same research program. They share the same author, Philip Shaw. From the first "We measured the thickness of the cortex across thousands of points in the brain in .. (466) children - half of whom had ADHD and half of whom did not" and from the second "They recruited 234 children with ADHD and 231 typically developing children ... they were able to map the trajectories of surface area development at over 80,000 points across the brain." Even though they appear to be different efforts (the number of children involved are different and the years are different), there might still be some spurious correlations solely because the same people, with the same expectations and analysis technique, are involved. Unfortunately, I am unable to read the primary literature. The first links to a paywalled journal article ($31.50), the second doesn't have a journal citation. I found http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3342014/ http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3342014/ by the same author, and published a couple of months after the article in the first link. Unfortunately, which it says there are distinguishable features, along with two reference comparisons, it doesn't give enough information to judge if those differences are truly diagnostic. I did find http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3440402/ http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3440402/ which comments "The ADHD diagnosis rests only on these symptoms because no biological markers (e.g. genetic tests, brain imaging) have been validated [11]", but that reference [11] is from 2006, and older than the two links you gave. A 2007 metaanalysis (so again, older than the two references you gave) at http://www.ncbi.nlm.nih.gov/pubmed/16950217 http://www.ncbi.nlm.nih.gov/pubmed/16950217 points out that at that time "Although there are many structural neuroimaging studies of attention-deficit/hyperactivity disorder (ADHD) in children, there are inconsistencies across studies and no consensus regarding which brain regions show the most robust area or volumetric reductions relative to control subjects." To highlight the intent behind those last two previous paragraph, they are saying that there are many studies like the ones you pointed out, which show a correlation between some physical measurement and ADHD. Unfortunately, they don't seem to be consistent. Because of the well-known publication bias problem, it's likely that false positives are over-reported. It takes additional followup work to determine if those signals are really true, and if they are distinguishable enough to be used diagnostically. This all tells me that there is no "large structural brain difference", and especially not one which has been validated as a diagnostic tool. There might be a small structural brain difference, but again, I find no evidence that identification of this difference is available as a diagnostic tool at all, even if the price were disregarded. Again, I might be focusing on the wrong thing, but perhaps you may be misinformed? If most of your research is through the popular literature, then my earlier reference to http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3440402/ http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3440402/ ("Why Most Biomedical Findings Echoed by Newspapers Turn Out to be False: The Case of Attention Deficit Hyperactivity Disorder") may be useful: > Because newspapers preferentially echo initial ADHD findings appearing in prominent journals, they report on uncertain findings that are often refuted or attenuated by subsequent studies. If this media reporting bias generalizes to health sciences, it represents a major cause of distortion in health science communication.