Stress caused by events such as moving, changes in family relationships and death can raise a child's risks for asthma attacks four-fold, according to a study in the latest issue of the journal Thorax.

The British study found that stressful life events were linked to bouts of acute asthma at two distinct time periods -- first, within two days of the worrying event, and then again six weeks later.

Researchers from University College London studied 60 children, aged 6 to 13, who'd had asthma for at least three years. For 18 months, the children kept daily diaries in which they recorded acute asthma attacks and their breath strength (peak flow). The children were checked every three months at a clinic, and their parents were also interviewed about potentially stressful life events occurring over the same period of time.

The main stressful life events experienced by the children included moving, births, deaths, departures, illness/hospital visits, separations, and changes in family relationships. During the study period, the children in the study experienced a total of 124 stressful life events and recorded 361 episodes of rapidly worsening asthma symptoms.

When they analyzed the data, the researchers concluded that the children were more than four times more likely to suffer a sudden worsening of asthma symptoms within a day or two of experiencing a stressful life event.

After a period of calm, the risk of worsening asthma symptoms suddenly doubled again about five to seven weeks after the stressful life event, the researchers add.

The immediate and delayed stress-related effects on asthma symptoms are likely caused by different physiological and immune processes involving the autonomic nervous system and hormone and brain chemical regulation, the researchers suggest.