Relaxation decreases large-airway but not small-airway asthma

Eleven asthmatic subjects were each offered sixteen sessions of relaxation therapy, consisting of progressive relaxation, desensitization, and EMG biofeedback to the trapezius and frontalis areas, while 9 subjects were offered a complex placebo. Subjects in the relaxation condition showed greater improvement than subjects in the placebo condition in performance on a methacholine challenge test which, as a measure of airway reactivity, reflects degree of asthma. Subjects in both conditions showed improvements in various self-report measures of asthma symptoms and psychopathology. Subject in the relaxation condition reported a significantly greater decrease in frequency of emotional precursors to asthma attacks than subjects in the control condition. Overall improvement on the methacholine challenge test was predicted almost perfectly by heliox spirometry. Only subjects showing predominant large-airway obstruction obstruction improved on the methacholine challenge test. The relative contribution of large airway obstruction to asthma was found to correlate with psychopathology.