If you're talking about the medical model, and if you define “specialty” in that way, like a cardiologist is a doctor specialized in cardiology, specialties don't exist per say in psychology in Quebec.
Each psychologist who is a member of his or her professional order is responsible, under the Code of ethics, to provide services and take measures only within the limit of his or her skills, training and rights as a psychologist.
That being said, when it comes to training, certain psychologists choose to work at the community level, others in groups, and yet others in a clinical setting. Clinical psychologists can develop expertise in the treatment of post-traumatic stress syndrome. Yet the field of clinical psychology is extremely vast.
So it really all depends on the area the psychologists has chosen to train in and the environment. The institutions which provide psychological services indicate to universities and other educational institutions the specific areas where psychologists are needed. Some psychologists become extremely specialized in their field, such as working with autistic children.
In Quebec today, there are nearly 2,000 psychologists who have been trained to treat post-traumatic stress syndrome. There are no statistics which might indicate how many of them treat Quebec's veterans. Saint-Anne Hospital has an employee support program which retains the services of 900 psychologists for its people in Canada.