Acetaminophen use and Autism.

A review of: Schultz, S.T., Klonoff-Cohen, H.S., Wingard, D.L., Akshoomoff, N.A., Macera, C.A., Ming Ji, . (2008). Acetaminophen (paracetamol) use, measles-mumps-rubella vaccination, and autistic disorder: The results of a parent survey. Autism, 12(3), 293-307. DOI: 10.1177/1362361307089518

A study in the latest issue of the journal Autism examined the possible role of acetaminophen use after MMR vaccine and autism. The authors provided an excellent review of the MMR vaccine-autism research, which indicates that although some clinical studies have found a link, most epidemiological studies have failed to find an association between MMR and autism. The authors noted that acetaminophen is commonly used to treat the adverse reaction of MMR vaccinations such a fever and rash. In addition, one study (Alberti et al, 1999) showed that some low functioning children with autism process acetaminophen differently. Thus, the authors proposed a innovative hypothesis: Does acetaminophen use after MMR vaccination increase the risk for Autism?

The authors recruited parents of typically developing children and children with autism via internet advertisement. The total sample included 83 parents completing the survey for children with autism and 80 parents completing the control survey. The surveys included a variety of questions about the child such as age, gender, what medications were used to prevent or treat reactions to the MMR vaccine, including aspirin, acetaminophen, or ibuprofen. The survey of parents of children with autism included additional questions about their children diagnosis such as whether a regression in development was observed.

The authors found that parents of children with autism reported:
- more adverse effects of MMR vaccine, including fever, diarrhea, irritability
- increased presence of concurrent illnesses with MMR vaccine
- more acetaminophen use after the MMR vaccine among children who had a reaction to the vaccine, children who had a regression in development, and those under 5.
- more acetaminophen use between 12 and 18 months of age
No association was found between ibuprofen use and autism.


A few caveats:
The finding that parents of children with autism reported more adverse effects of MMR vaccine or more concurrent illnesses with MMR vaccine is not overly informative. Note that these results were based on parental reports via internet with no possibility of verification of accuracy of such reports. So it is completely plausible to argue that given the extended media coverage of the vaccine-autism link, some parents of children with autism are more attuned to their children histories after vaccination and thus are more likely to remember or report complications. What is informative and actually interesting is that there was a significant difference in reports of acetaminophen use as compared to ibuprofen use. This difference can not easily be explained on the basis of some report bias. The problem is that acetaminophen use was reported much more frequently than ibuprofen use by all parents. So it could be argued that since parents of children with autism were more likely to report complications (even if just a by-product of recall bias), the use of acetaminophen will also appear to be different between the two groups.

Perception of voice gender in high functioning autism

A review of: Groen, W.B., Orsouw, L., Zwiers, M., Swinkels, S., Gaag, R.J., Buitelaar, J.K. (2008). Gender in Voice Perception in Autism. Journal of Autism and Developmental Disorders DOI: 10.1007/s10803-008-0572-8

Social perception using non-verbal means, such as recognition of the social information embedded into facial expressions, voices, and gestures, play a key role in social communication. Unlike typically developing kids, babies that are later diagnosed with autism do not show a preference for their mother’s voice as apposed to other voice sound. The authors of this study reviewed this and other evidence of atypical sound processing in autism, specially the finding that people with high functioning autism have an atypical cortical processing of voices when compared to typically developing kids. Based on these findings, the authors wanted to explore if theses differences in sound processing result in impaired ability to recognize the gender of a speaker base solely on voice perception.

The study included 20 adolescents with high functioning autism and 20 typically developing adolescents who were matched for IQ, gender, and age. Diagnoses were based on DSM-IV criteria and confirmed via ADI. The participants were presented voice fragments via headphones and were instructed to determine whether the voice was of a male or a female. The authors used a specialized software to morph the gender of the voices and thus present fragments that slowly changed from stereotypically masculine to stereotypically feminine.

The authors did not find any group differences in the accuracy for identifying the correct gender. Typically developing kids and those with high functioning autism were as accurate when identifying the gender of voice fragments. However, significant differences were observed in the speed of responding but only for the originally male morphed voices (male to female morph).

Please note however, that the differences in response time were not simple a 'mean' difference with those with HFA responding slower than typically developing kids. Instead, typically developing kids had a linear increase in response time as the voices were morphed. For example, they responded much faster when the voice was not morphed (original male voice presented as male voice) but gradually increased their response time as the voices were morphed, so that the slowest response time was when the voice was completely morphed (original male voice presented as a female voice). However, for those with HFA the effect was not linear. They responded fast when the voice was not morphed, slowed as the voice began to get morphed, but then became fast again when the voice was completely morphed.

The authors conclude that children with high functioning autism are not impaired in the perception of voice gender, but instead use a different perceptual approach resulting in different response times.