Under section 2 of the IAODA, industrial accident means a sudden and unforeseen event, attributable to any cause, which happens to a person, arising out of or in the course of his work and resulting in an employment injury to him.

Under section 28 of the Act, there is a presumption in favour of the worker when he is victim of an injury arising out of or in the course of his work. As regards the examination of claims for mental injuries related to an industrial accident, the Commission des lésions professionnelles (CLP) nevertheless considers that this presumption does not apply since mental injuries are not in themselves injuries. Consequently, any claim for a mental injury implies that the worker must demonstrate, through preponderance of evidence, the causal link between one or more events arising out of or in the course of work and the mental disease.

In this context, the worker can refer to the occurrence of a shock event such as an explosion, an aggression, a shooting, etc. or he can claim that the mental injury is caused by a succession or a series of overlapped events spreading over a certain period of time. In this latter case, all the events must correspond to the notion of a sudden and unforeseen event which implies a situation that goes beyond the normal context of work.

It should be mentioned that, in general, claims are more often examined as industrial accidents than occupational diseases.

Pursuant to the IAODA, occupational disease means a disease contracted out of or in the course of work and characteristic of that work or directly related to the risks peculiar to that work.

As regards the claims presented as occupational disease, pursuant to section 29 of the IAODA, no mental disease is presumed to be related to work. The worker must therefore demonstrate, through preponderance of evidence, that there is a causal link between the disease that he has developed and his work. Thus, he can either claim that the disease is characteristic of the work he performs, that is, it was caused by the generic and general characteristics of that work, or claim that the disease is related to the risks peculiar to that work, namely the working conditions that led him to develop these problems.