The main objective of this preliminary randomized controlled clinical trial is to establish efficacy and feasibility of a yoga-based treatment for PTSD in military veterans as compared to a delayed yoga treatment (waitlist control) group. Secondary objectives are to evaluate PTSD characteristics that may also be improved with the treatment and acceptability and compliance with the treatment.

Specific Aims:

1. To evaluate the hypothesis that a 10-week yoga-based intervention will reduce PTSD severity to a statistically and clinically significant degree relative to a pretreatment baseline evaluation and to a waitlist control group.
2. To evaluate the hypothesis that PTSD patients will show improvement in regulation of physiological arousal in the autonomic nervous system relative to pretreatment.
3. To evaluate that hypothesis that symptoms associated with PTSD such as depression, anxiety, insomnia and quality of life will also be improved.
4. To evaluate the hypothesis that military veterans with PTSD can be successfully recruited into a yoga intervention study and will find the intervention acceptable and tolerable and will exhibit high compliance.

Inclusion Criteria:

• Male and female military veterans and active duty military personnel aged 18 and older
• A DSM IV diagnosis of post-traumatic stress disorder
• Potential subjects on medications are eligible to participate in the study
• Potential subjects who receive ongoing medical or psychological treatment are eligible to participate in this study as long as these treatments do not include more than one hour weekly of relaxation and mind-body based stress reduction strategies (strategies directly related to meditation and yoga)
• Potential subjects are eligible to participate in this study if they have sufficient mental and physical ability to fully participate in the parameters of the study. Subjects must be able to understand and comply with instructions in the group yoga sessions and home practice, complete questionnaires, participate in clinical interviews, and take part in all data collection activities. Subjects with severe mental or physical concerns that may prevent them from understanding and/or complying with the treatment will be excluded. For example, potential subjects confined to wheelchairs will not be eligible, although subjects with artificial limbs who are able to reasonably participate in the intervention may be deemed eligible. These determinations will be made during discussions with potential subjects on a case by case basis during the screening process

Exclusion Criteria:

• Potential subjects are ineligible if pregnant and in their third trimester.
• Potential subjects are ineligible if they are confined to a wheel chair.