A pilot study is currently in progress.

Patients with post traumatic stress disorder (PTSD) will be randomized to a 12-week intervention of Sudarshan Kriya Yoga Trauma Relief Program (SKY) or a wait list control (WLC) to assess the effects of this intervention on symptoms of PTSD, depression, anxiety, quality of life, autonomic symptoms, and blood inflammatory markers.

A single-center, single blind longitudinal randomized controlled naturalistic trial comparing a 12 week Sudarshan Kriya Yoga Trauma Relief Program (SKY) intervention to a wait list control (WLC) group.

Research participants will be men and women, 18-75 years of age, who have PTSD. The study will recruit from the general adult ambulatory mental health clinics as well as the geriatric mental health program in London.

Potential participants will be screened as per inclusion and exclusion criteria by trained research staff. These patients will already have clinically diagnosed PTSD by a psychiatrist and any other comorbid diagnoses would have already been confirmed. However, for research purposes a diagnosis of PTSD will be confirmed through a structured clinical interview specifically the MINI (Mini International neuropsychiatric Interview) and the Clinician-administered PTSD Scale for DSM5- past month version (CAPS5). CAPS5 will also be used to rule out exclusion criteria of severe depersonalization and derealization. The scales will be administered by a trained research staff and confirmed by a psychiatrist.

The MINI will also be used to assess for suicidality. If the total score on Questions C1 and C2 is more than 5 at any time during the study then this will be reported to the PI who will further assess the patient for safety and risk assessment.

If the participant is above the age of 65 years of age they will also be asked to complete a cognitive screening test (Mini Mental State Examination, MMSE) to ensure they are not suffering from any memory impairments.

Participants who meet the inclusion criteria will be randomized to either SKY or WLC with equal probability (1:1) using computer generated randomisation numbers. Concealment of randomisation to outcome assessors and investigators will be ensured by an independent staff member who will perform the randomisation using a third party web based provider. Computerised randomization will take place in the Geriatric Mental Health Program outpatient unit in London Health Sciences, London, Ontario. A telephone number will be available for study concerns/queries. Pre-randomized information will be stored using unique de-identifiers and downloaded on a secure database. It will not be possible to blind participants to intervention status hence the single-blind design.

SKY training involves attending a week-long (6 days) course that teaches the basic principles of SKY over 2.5-3 hour daily sessions. This will be followed by once weekly follow up sessions (90 min/wk) for 3 weeks and then bimonthly sessions (every 2 weeks) for the next 8 weeks. In addition, participants will be asked to practice SKY at home daily (25 min/day) throughout the duration of the study period and log practice frequency and any other noteworthy observations in a log sheet that will be provided to them (please see attached log sheet). Meals will be provided for 2 days during the initial SKY training course and nutritional snacks on the other 4 days.

Participants randomized to the control arm of the study will continue to receive their treatment as usual, including pharmacotherapy and/or psychotherapy. They will follow assessment and study procedures as listed below. Upon completing the initial 12 weeks of the study, participants in the WLC arm will also be offered the opportunity to learn SKY and attend follow up therapy sessions; that is, WLC participants will be offered the same intervention as the SKY group received in the first 12 weeks of the study. No study procedures will be applied or any other information collected during this period except for a final assessment that will take place at 24 weeks (see below).

Inclusion Criteria:

1. Have an Axis 1 diagnosis of PTSD as per CAPS5 (Clinician Administered PTSD Scale for DSM 5- past month version) criteria.
2. If participants are using antidepressants, they must be at therapeutic doses for a minimum of four weeks prior to commencing the study. Patients who are not willing to take any medications will also be eligible for the study
3. Sufficient hearing to be able to follow verbal instructions and able to sit without physical discomfort for 60 minutes.
4. Willing and able to attend 6 initial SKY training sessions and 75% of follow up sessions
5. Not pregnant and willing to remain not pregnant for the duration of the study

Exclusion Criteria:

1. They are currently participating in other similar studies.
2. If the patient scores severe or extreme on Depersonalization (item 29) or Derealization (item 30) items of CAPS5.
3. Other significant mental health diagnosis including substance dependence, Neurocognitive disorder, Obsessive Compulsive Disorder, Panic Disorder, Bipolar disorder and/or Personality disorder (confirmed by Psychiatrist and MINI)
4. High risk of suicide as elicited by clinical interview (MINI).
5. Psychotic episodes within the past 12 months.
6. Traumatic Brain Injury (TBI) as defined by loss of consciousness for more than 20 minutes and/or Glasgow Coma Scale score less than or equal to 12. (The researcher will use self-reported histories to screen for traumatic brain injury and if necessary confirmed by medical records.
7. Currently practicing any type of formal meditation, mindfulness or breathing techniques regularly.
8. Serious cardiovascular disease in the past 12 months (i.e. myocardial infarction, stroke, TIA, uncontrolled hypertension), or a past history of neurological disease (including Parkinson's Disease), seizures, or diabetic neuropathy
9. Major surgery within 6 weeks prior to commencement of the intervention, or a scheduled major surgery during the intervention period. (This is due to the physical rigor of the breathing techniques).