Complex sentence: An important difference is that the Canadian definition excludes patients with symptoms of mental illness and may be better than the CDC 1994 definition at distinguishing CFS cases from psychiatric cases and individuals experiencing chronic fatigue.
Split into simpler sentences: An important difference is that the Canadian definition excludes patients with symptoms of mental illness. This definition may be better than the CDC 1994 definition at distinguishing CFS cases from psychiatric cases and individuals experiencing chronic fatigue.