Children with asthma face quadruple the risk of an attack following stressful events in their lives, according to a study published in the journal Thorax. Researchers from McGill University in Montreal, Canada, studied 60 children between the ages of 6 and 13, who had suffered from asthma for at least three years.

The children were asked to keep daily records over 18 months of acute attacks and their breath strength. Researchers regularly interviewed the children and their parents about stressful life events. After the information was analysed, the children were found to be four times as likely to experience a sudden worsening of symptoms within two days of a traumatic experience. The most upsetting events were cited as moving house, births, deaths, separations and changes in family relationships.

Researchers found double the risk of symptoms worsening again about six weeks after the event. Past studies have indicated that stress and states of emotional arousal produce increased airway resistance.

The authors of the study, published on Wednesday, suggested the increased likelihood of asthma attacks was due to a variety of physiological and immune processes involving the nervous system as well as hormone and brain chemical regulation.