This document provides information on common mental health presentations in the emergency department (ED) and the role and tools available to ED doctors in assessing and managing these patients. It discusses challenges including resource intensity, safety risks, and legislation. Key responsibilities of the ED doctor are to stabilize the situation, conduct a risk assessment, check for any underlying medical issues, and determine an appropriate care location. Tools include clinical skills, medications, collaboration with mental health teams, and knowledge of relevant legislation. A mental state examination and structured risk assessment are important clinical skills.