The research also demonstrates that seeing the child experience their wish was positive for the parents, while often it provoked bittersweet feelings.

The study, published in Acta Paediatrica and led by Dr Anne-Sophie Darlington, Senior Research Fellow at the University of Southampton, Professor Passchier and Dr Heule at the Erasmus Medical Centre in the Netherlands, interviewed and surveyed 235 parents of children who had been granted a wish by the Make-A-Wish Foundation in the Netherlands.

Parents were asked about their general impression of the wish and whether they felt it improved wellbeing and coping after the event. Parents who had sadly lost their child before the study were asked if the wish had influenced their bereavement.

Results showed that almost all parents (92 per cent) indicated that the experience was a positive one and the majority agreed that their child momentarily did not feel ill during the event. Parents also said their child was distracted from their situation.

Parents said that it was an important memory for them, although a minority thought their child's quality of life had increased after the event.

Parents (47 per cent) admitted that they often felt sad and conflicted as well as happy; they were happy their child received their wish but sad that they were eligible for a wish.

For those parents whose child had died before the start of the study, 21 per cent felt the wish fulfilment helped with bereavement.

Dr Darlington comments: "There has been a growing interest in the influence of positive events on wellbeing, especially of those people who are ill. Many organisations organise events with the hypothesis that these events improve the lives of the recipients. However research on such activities and their impact has been fairly scarce.

"Our study has shown that on the whole the experience is a positive one with children experiencing more energy and parents being distracted. However, longer term effects were only found for a small group of parents and children. We are very grateful to the parents for taking part in our study."