An operational stress injury (OSI) is a term used most often to describe mental disorders which result from, or are exacerbated by, military or police service. In the Canadian context, this most often refers to active or former members of the Canadian Armed Forces (CAF) or the Royal Canadian Mounted Police (RCMP). The most common diagnoses within this term include post-traumatic stress disorder (PTSD), anxiety disorders, depression, and substance use disorders.
