I feel some of this is being reported as "mind blowing and life changing results" when presented in books, blogs and media meant to be consumed by the every day person.
Snake oil has always existed; people will always line up to buy the next best thing, if they want it badly enough.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3573542/
There is mounting evidence to suggest that SKY can be a beneficial, low-risk, low-cost adjunct to the treatment of stress, anxiety, post-traumatic stress disorder, depression, stress-related medical illnesses, substance abuse, and rehabilitation of criminal offenders.
Key word: adjunct.
I think what is tough for people struggling with any mental illness is this: by the time a person is symptomatic enough to recognize that it's not just their imagination, they will be too symptomatic to navigate the great big maze of mental health care. 'What's wrong with me' and 'where do I go to get help' are two pretty common questions, I think. Now that we have the medical school of the internet, people can start researching and plugging in symptoms, and will either find their way to the right kind of support...or they won't.
Can PTSD - actual, legit PTSD - be managed through breath-work alone? As a person with the disorder, my opinion is a strong, 'no'. Can breath-work be a really helpful addition to a sufferer's routine? My opinion, yes. I think it's premature for anyone to advertise that they have a better or more effective treatment for PTSD, when PTSD itself has not been fully, scientifically, resolved.
But much of this depends on where a sufferer is at when they enter a search for treatment. Have you limited your parameters in any way - are you looking at people who have already been diagnosed, undergone some portion of therapy, or who are just starting out and not even sure what's wrong with them? Here on our forum you'll find a real cross-section, but there are many different points of comparison: what the DSM-5 and the ICD-10 say, what pop journals like psychology today, science daily, etc. say, what devotees of various authors like Levine, Van Der Kolk, Kabat-Zinn, etc., say - it kind of goes on, and on. There's medication, and the FDA, and no medication, or 'alternative' medication, there's diet, non-inflammatory foods...
What's your masters in? I'd imagine it could be a number of things (and please forgive me if you said it and I missed it). And, just to do my due diligence as Admin - depending on the exact type of study you are doing - do you have an informed consent form for human subject research?