The term emergency is used throughout this document as it is defined in the Civil Contingencies Act (2004). It describes an emergency as:

• an event or situation which threatens serious damage to human welfare
• an event or situation which threatens serious damage to the environment or
• war or terrorism that threatens serious damage to security

Other terms are used as follows:

Psychosocial refers to the psychological, emotional, social and physical experiences of people in the context of emergencies.

Reaction refers to the experiences, difficulties and problems that may affect people after emergencies.

Mental disorder refers to a clinically recognisable set of symptoms and behaviours which are generally associated with distress or disability, where people’s reactions, emotions and behaviours are more intense, frequent, sustained or incapacitating than might be expected of the general population.

Social support refers to the social interactions that provide people with actual assistance, and which also embed them in a web of relationships that they perceive to be caring and readily available in times of need.

The document distinguishes between those psychosocial reactions that are very common and not usually pathological, and mental health reactions that may be symptomatic of mental disorder. Both kinds may have emotional, psychological and behavioural components. Needs that arise from psychosocial reactions are termed psychosocial needs, and needs that relate to mental health reactions are termed mental health care needs.