Expressed emotion occurs in families where a member is suffering from a mental-health problem. It is made up of three elements: hostility, a negative attitude towards the patient because the family feels the disorder is controllable and that the patient is choosing not to get better; emotional over-involvement when the family blame themselves for the mental illness and critical comments. High expressed emotion has been associated with a slower recovery and a greater likelihood of relapse. A team of Dutch researchers from Utrecht University looked into the links between maternal expressed emotion and mental-health problems in a study of 497 Dutch teenagers and their mothers. Every year, over three years, the mothers were asked about their expressed emotion and the teenagers about their behavioural and emotional problems. The main conclusion of the research was that it was the children's level of emotional and behavioural problems that influenced the mother's expressed emotion and not vice versa.
Hale III, William ... [et al] - How does longitudinally measured maternal expressed emotion affect internalizing and externalizing symptoms of adolescents from the general community? Journal of Child Psychology and Psychiatry doi:10.1111/j.1469-7610.2011.02400.x