Mood disorders, especially depression and anxiety, play an important role in the exacerbation of pain perception in all clinical settings.Depression commonly occurs as a result of chronic pain and needs treating to improve outcome measures and quality of life.Anxiety negatively affects thoughts and behaviours which hinders rehabilitation.Anxiety and depression in acute hospital settings also negatively affect pain experience and should be considered in both adults and children.Poor pain control and significant mood disorders perioperatively contribute to the development of chronic postoperative pain.