In Brief:
Anxiety is common among individuals with asthma, which worsens their asthma management and symptoms. However, little progress has been made in treating such patients. The findings of this study suggest that a brief biofeedback intervention designed to raise Pco2 led to significant and sustained increases in Pco2 and reductions in anxiety sensitivity and negative affect, compared with slow-breathing training. The findings support Pco2 as a potential physiological target for anxiety reduction in asthma.