Evaluation of Yoga for Sleep Disturbances in Post Traumatic Stress Disorder (PTSD)

Inclusion Criteria: * Male and non-pregnant female adults at least 18 years of age. * A DSM-IV-TR diagnosis of post-traumatic stress disorder (PTSD). * Naïve to yoga and other meditative practices, defined as less than one hour per week for the past 6 months. * Potential subjects receiving ongoing medical or psychological treatment are eligible, as long as treatment remains stable over the course of the study and does not include more than one hour weekly of mind-body medicine (strategies directly related to meditation and yoga). * No more than 2 alcoholic or caffeinated drinks/day * No illicit drug use * Potential subjects are eligible if they have been on stable dosage (not PRN) of medication for PTSD symptoms including sleep disturbances and any medication that may influence sleep for at least 6 weeks prior to the study, and be willing to continue with same dosage for the duration of the study. * No current substance abuse, defined as diagnosis of substance abuse or dependence disorder within the past year, and/or in/outpatient treatment for substance abuse or dependence in the past 6 weeks. * No transcontinental travel over the course of the study. * No night-shift or rotating shift work over the course of the study. * Insomnia based on the American Academy of Sleep Medicine's Research Diagnostic Criteria (RDC) for insomnia due to a mental health disorder * 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.