4 ms·

Having some traits that resemble autism isn't the same as having an atypical brain. But even assuming that's true (which I don't think is actually known) how w

Having some traits that resemble autism isn't the same as having an atypical brain. But even assuming that's true (which I don't think is actually known) how would you distinguish them? There isn't yet a genetic test or an antibody test or anything like that to distinguish autistic from non-autistic people, right? So it's based on judging the symptoms; and given there's a wide spectrum of symptoms, the categorisation is always going to be somewhat arbitrary.

zepto 6y ago
I think that the results of the study in question suggest that you can distinguish a real systematic difference even from the stochastic data.
- skissane 6y ago
  In practice, reliably distinguishing ASD from non-ASD is problematic. [0] is a PhD thesis which (in its first part) examines three specialist ASD diagnostic clinics in the US, with a >30% percentage point difference in diagnosis rates. It argues that the best explanation for that observed difference is differences in clinical culture between the clinics; and, that despite this substantial variation in diagnosis rates, the clinics took an unusually rigorous approach to diagnosis, suggesting that in a broader set of clinics (most of whom would approach diagnosis with less rigour) the variation is likely to be even higher. Although we have diagnostic instruments, such as the ADOS-2 (which along with the ADI-R is considered the "gold standard"), they have problems. One problem is that the standards for using these instruments clinically are a lot weaker than the standards for research use. [1] is a study which attempts to measure the accuracy of ADOS(-2) coding by clinicians, by comparing it to the consensus coding of experienced researchers – it found a high variability in the accuracy of the clinical codings – some clinicians were quite close to the research standard, others were a fair way off. [0] https://dspace.mit.edu/handle/1721.1/90070 https://dspace.mit.edu/handle/1721.1/90070 [1] https://pubmed.ncbi.nlm.nih.gov/29560529/ https://pubmed.ncbi.nlm.nih.gov/29560529/
  - zepto 6y ago
    “In practice, reliably distinguishing ASD from non-ASD is problematic.“ Agreed, but it’s not clear why that is relevant. Whether it is hard to diagnose or not doesn’t tell us whether the condition is discrete or distortion on a spectrum.
    - skissane 6y ago
      Well, if we view the "spectrum" as including broad autism phenotype (BAP), and note that that the boundary between ASD and BAP can be very difficult to reliably determine, that seems to me to support the "distortion on a spectrum" viewpoint. By contrast, if BAP didn't exist, or if there was a highly reliable test to distinguish it from ASD, that would not support that viewpoint. So the reliability of distinguishing BAP from ASD does actually seem to me to be relevant to the issue. I think the answer to "whether the condition is discrete or distortion on a spectrum" is likely to be "both". I think the most severe cases – such as non-verbal classic Kannerian autism with intellectual impairment – are likely discrete conditions (albeit not a single discrete condition, more likely several). By contrast, the lower severity cases are likely to just be the extreme end of the normal variation of traits in the general population. I think, one of the many mistakes made by the authors of the DSM-5, was creating a single diagnosis encompassing everything from the most severe to the mildest cases, when it seems likely that rather different things are going on at those two extremes. There's a bunch of research that supports that view, see for example: https://link.springer.com/article/10.1007%2Fs10803-017-3451-3 https://link.springer.com/article/10.1007%2Fs10803-017-3451-...
      - iainmerrick 6y ago
        So taxonicity is dimensional, not categorical? :)

zepto 6y ago

I think that the results of the study in question suggest that you can distinguish a real systematic difference even from the stochastic data.

skissane 6y ago
In practice, reliably distinguishing ASD from non-ASD is problematic. [0] is a PhD thesis which (in its first part) examines three specialist ASD diagnostic clinics in the US, with a >30% percentage point difference in diagnosis rates. It argues that the best explanation for that observed difference is differences in clinical culture between the clinics; and, that despite this substantial variation in diagnosis rates, the clinics took an unusually rigorous approach to diagnosis, suggesting that in a broader set of clinics (most of whom would approach diagnosis with less rigour) the variation is likely to be even higher. Although we have diagnostic instruments, such as the ADOS-2 (which along with the ADI-R is considered the "gold standard"), they have problems. One problem is that the standards for using these instruments clinically are a lot weaker than the standards for research use. [1] is a study which attempts to measure the accuracy of ADOS(-2) coding by clinicians, by comparing it to the consensus coding of experienced researchers – it found a high variability in the accuracy of the clinical codings – some clinicians were quite close to the research standard, others were a fair way off. [0] https://dspace.mit.edu/handle/1721.1/90070 https://dspace.mit.edu/handle/1721.1/90070 [1] https://pubmed.ncbi.nlm.nih.gov/29560529/ https://pubmed.ncbi.nlm.nih.gov/29560529/
- zepto 6y ago
  “In practice, reliably distinguishing ASD from non-ASD is problematic.“ Agreed, but it’s not clear why that is relevant. Whether it is hard to diagnose or not doesn’t tell us whether the condition is discrete or distortion on a spectrum.
  - skissane 6y ago
    Well, if we view the "spectrum" as including broad autism phenotype (BAP), and note that that the boundary between ASD and BAP can be very difficult to reliably determine, that seems to me to support the "distortion on a spectrum" viewpoint. By contrast, if BAP didn't exist, or if there was a highly reliable test to distinguish it from ASD, that would not support that viewpoint. So the reliability of distinguishing BAP from ASD does actually seem to me to be relevant to the issue. I think the answer to "whether the condition is discrete or distortion on a spectrum" is likely to be "both". I think the most severe cases – such as non-verbal classic Kannerian autism with intellectual impairment – are likely discrete conditions (albeit not a single discrete condition, more likely several). By contrast, the lower severity cases are likely to just be the extreme end of the normal variation of traits in the general population. I think, one of the many mistakes made by the authors of the DSM-5, was creating a single diagnosis encompassing everything from the most severe to the mildest cases, when it seems likely that rather different things are going on at those two extremes. There's a bunch of research that supports that view, see for example: https://link.springer.com/article/10.1007%2Fs10803-017-3451-3 https://link.springer.com/article/10.1007%2Fs10803-017-3451-...
    - iainmerrick 6y ago
      So taxonicity is dimensional, not categorical? :)