Kathryn McKay from the Simon Fraser University sent the following question:
Hello,
I am looking for articles from the late 19th or early 20th century that describe the mental conditions of Native Americans and First Nations peoples from a medical perspective, rather than from an anthropological one. The earliest I have found are Dr. Hummers'”Insanity among the Indians” from 1911, Dr. A.A. Brill’s “Piblokto or Hysteria among Peary’s Eskimos,from 1913” and Dr. I Coriat’s “Psychoneuroses among primitive tribes”from 1915.
Please let me know if you know of anything earlier. I am particularly interested in dementia praecox, but am more generally interested in any discussion of “insanity.”
I can be reached at mckay@sfu.ca
h-madness 
Probably of some interest regarding the US neurologists’ vision of the native people’s cultivation of unusual mental conditions is :
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2511273/?page=1
Hi Kathryn,
There is no exact date, but I found this: Mental Health Among Natives: A Collection of Articles and Reports from Various Sources. 1900s. May only be available at a university in Nova Scotia, though…
Also, maybe Carla Joinson, author of the Canton Asylum for Insane Indians blog, may have some leads: http://cantonasylumforinsaneindians.com/history_blog/
Daisy