Sometimes our ancestors ended up in Insane Asylums not because they were insane but for other reasons - post partum depression in women, menopause, depression... any number of occurrences could land an individual in an asylum.
Olive Tree Genealogy has an Insane Asylum section which includes England, Scotland, Australia and Canada. One database in particular may be of interest to Canadian genealogists.
Toronto Insane Asylum 1841
ABSTRACT of PATIENTS admitted, discharged, and remaining in the
temporary Lunatic Asylum, Toronto, Ontario, Canada from January 21st to
July 31st, inclusive, 1841