The manual is designed for members of the public to learn how to offer initial assistance to someone who is developing a mental health problem or is in a mental health crisis. The developing mental health problems covered include depression, anxiety problems, psychosis, substance use problems and gambling problems. The mental health crises covered are: suicidal thoughts and behaviours, non-suicidal self-injury, panic attacks, reactions following a traumatic event, severe psychotic states, severe effects from substance use and aggressive behaviours. The giving of mental health first aid is most relevant in situations when it is first becoming apparent to others that a person in their family or social or professional network is developing a mental health problem. However, the manual may also provide some useful information on how to assist a person who has a history of a mental illness or longer-term mental health problems.