This guideline relates to increases in Emergency Department visits or NSW Ambulance Service calls for mental health, drug and alcohol problems identified by the Public Health Real-time Emergency Department Surveillance System (PHREDSS). It describes the flow of information via a situation report, from PHREDSS to the Office of the Chief Health Officer and the Mental Health and Drug and Alcohol Office. It identifies the situations in which each of these bodies has primary responsibility for deciding how to respond to the increase.