Not from Montreal, but still in the province, I would say you should contact a CLSC or a CRDI for more info. Would say the CRDI would be the best choice for they are one of the main organism for TED in the province, currently followed by one of their specialized educator.
Cannot really say specific place where you can get a adult diagnostic since I had it done while I was seeing a psychiatrist, at hospital, for depression and she had me see a neuropsychologist for different testing, the neuropsychologist is the one who gave the diagnostic.