Background. A majority of patients with asthma believe that psychological factors (particularly
stress) can induce asthma attacks, but empirical support for actual stress-induced airways
obstruction is controversial. This study tested the hypothesis that stress induces breathlessness and
not airways obstruction.
Methods. Stress was induced by a frustrating computer task in 30 adolescents with asthma and 20
normal controls, aged 14–19 years. Stress measures were self-reported emotions, heart rate, blood
pressure. Respiratory measures were respiratory rate (RR), end tidal CO2, deep inspirations and
sighs. Asthma measures were lung function, wheeze, cough, breathlessness.
Results. All measures confirmed high levels of negative emotions and stress. None of the
participants developed airways obstruction; they had no reduction in lung function, wheeze was
absent and cough negligible. However, breathlessness increased in all participants with asthma and
excessively in many. The mean breathlessness was higher than during induction of actual airways
obstruction with provocative agents in previous studies. End tidal CO2 showed that breathlessness
could not be explained by hypocapnia.
Conclusion. Stress can be sufficient to induce breathlessness in patients with asthma.