Canada is in between from my own experience (as always, others may have had different/better/worse experiences). My ADD diag was long and involved - a lot of testing of different types and medical tests to back up that it wasn't a medical issue causing the symptoms (ie -thyroid). Psychiatry is paid for by the provinces, and where it is hard getting a GP, I'd rather have a psychiatrist than a psychologist -as you said, talk therapy only goes so far. It also gave me the GAD, Social Anxiety and OCD co-morbid diags as well.

I think we use the DSM here mostly, but I do know that the WHO ICD is also used -- likely to cross reference, seeing as the DSM-IVTR SUCKS in some respects.