Studies in the past have shown how stress can influence a person's own health, but there has been less research on how it can affect the health of others. In the study, reported in the New Scientist magazine today, lead author Dr Mary Caserta and her team followed the health of 120 children over three years. The children aged between five and 10. Parents were asked to keep a weekly diary of the child's illnesses and to take a temperature measure when they got sick. Every six months the parents completed questionnaires that asked about their own psychiatric health as well as about stressful events and family conflict.
The researchers found a clear link between anxiety and depression among parents and an increased chance of the children being ill and having a high temperature.
The children of parents with more intense psychiatric symptoms also had a more active immune system, as measured by the level of ''natural killer'' cells and other immune components in their blood. This suggests their immune system was working harder.
The research, however, did not find evidence for any impact on the health of children of individual events such as family separation, neighbourhood violence or family injury, or general family conflicts.