A new study shows a sharp rise in salivary levels of cortisol soon after waking in typically developing 18-year-old men, but not in young men of the same age who have Asperger's syndrome.
That difference may be related to resistance to change in Asperger's patients, according to the researchers, who included Mark Brosnan, PhD, of the psychology department at England's University of Bath.
Brosnan and colleagues studied salivary cortisol levels in 20 young men with Asperger's syndrome and 18 typically developing men of the same age.
Salivary cortisol levels spiked half an hour after waking in the typically developing group, but not among the Asperger's syndrome group.
Not having that morning spike in cortisol levels may be linked to "an extreme need for sameness and resistance to change," Brosnan's team writes.
These findings don't prove that; it's not clear which came first, Asperger's syndrome or steady salivary cortisol levels in the morning.
"Although these are early days [in our research], we think this difference in stress hormone levels could be really significant in explaining why children with [Asperger's syndrome] are less able to react and cope with unexpected change," Brosnan says in a University of Bath news release.
The study appears online in Psychoneuroendocrinology.