1 Department of Medical Genetics, University of Alberta, Edmonton, AB, Canada.
2 Department of Psychiatry, Dalhousie University, Halifax, NS, Canada.
3 School of Public Health, University of Alberta, Edmonton, AB, Canada.
4 School of Epidemiology, Public Health and Preventative Medicine, University of Ottawa, Ottawa, ON, Canada.
5 Department of Psychiatry, University of Alberta, Edmonton, AB, Canada; Neuropsychology Service, Alberta Hospital Edmonton, Edmonton, AB, Canada. Electronic address: spurdon@ualberta.ca.