Mechanistic Pathways of Mindfulness Meditation in Post-traumatic Stress Disorder.

The slowed breathing group will be trained on a breathing device, RESPeRATE, designed to reduce respiratory rate.They will practice with RESPeRATE once a week (for 6 weeks) in the laboratory with the research staff.

The Mindfulness Body Scan meditation will be used for the mindfulness meditation group.Participants will be trained once a week (for six weeks) in the laboratory by the research staff.

A structured Mindfulness breathing will be guided by the research staff during the lab trainings. The participant will sit upright and attempt to focus attention on his or her own breath as it passes the opening of the nostrils or on the rising and falling of the abdomen or chest. Whenever attention wanders from the breath, the participant will simply notice the distracting thought and then let it go as attention is returned to the breath. Training will be given once every week for 6 weeks.

"The SQ control group's intervention will include sitting quietly and listening to a neutral-content book on tape to serve as a time and attention control at each laboratory session. They will also be asked to sit quietly at home daily."