Symptom prescription: inducing anxiety by 70% exhalation.

This study investigates the effects of partial exhalation to feelings of anxiety. Thirty five volunteer subjects (14 male, 21 female, mean age 40.6) were first trained in slow diaphragmatic breathing (SDB). Then subjects rated their anxiety levels on a scale from 1 (none) to 5 (extreme) in sequential conditions of SDB, 70% subjective exhalation, and SDB. During the 70% subjective exhalation phase, subjects were instructed to breathe and limit their exhalation to 70% of the inhaled volume during each consecutive breath. The 70% subjective condition significantly (P < .0005) increased subjects' anxiety levels as compared to the initial SDB baseline, while a return to SDB significantly reduced the anxiety levels. The 70% approach appears useful in demonstrating to the client that possible changes in breathing patterns can affect anxiety.