A couple of noteworthy authors/speakers on the topic are Dr. Gabor Maté and Dr. Bruce Lipton.
Dr. Maté is a mainstream physician who was born into a Jewish family in Hungary just as the Nazis were occupying. Through his career he has closely studied the role of early life trauma in long-term behavioural and physiological illness. Here's an article he wrote about autism . He's written a bunch of books about links between trauma and long-term health outcomes .
Dr. Lipton was a pioneering stem cell biologist in the 70s and 80s, who became particularly interested in the role of experience/belief/trauma on behavioural and physiological outcomes. In his book, The Biology of Belief , he covers the statistical link between early life trauma and autism, and proposes a biological basis for it.
Lipton is a controversial figure who is easily ridiculed by mainstream medicine devotees as he gets handwavy about quantum physics and has become involved with the new age spirituality movement. But, having applied his ideas very successfully in my own life over the past few years, I can attest that what he's right about is more important than what he might be wrong about.
I should emphasise that anyone experiencing mental illness should consult a mainstream psychiatrist first, in case they need medication or other professional care. The techniques below are for people who have a solid baseline of mental health, but want to find better success and happiness in their career, relationships, etc.
For NET, search for "NetMindBody" and find a local practitioner. They're all over the world. Alternately, look for Psych-K or BodyTalk System - they're variants of the same concept. Ultimately you'll want to learn how to do it yourself rather than paying a practitioner, so you can search Meetup.com for "muscle testing" and you might find a local group and meet some like-minded folk on the same journey.
For "holotropic breathwork", a Google search will point you to solid info and local instructors. FYI it was conceived by Stanislav Grof, a psychiatrist who pioneered research into LSD before it was outlawed.
EFT/tapping is all over YouTube. Its biggest proponents push it as a be-all-and-end-all, but for me it's only been a small component of the overall approach, though still an important one at times.
Practitioners of Erickson hypnosis are everywhere, so it should be easy to find someone local. This one has also been minor for me but still valuable.
A well-known book offering some science behind the mind/body congruence concept is Bruce Lipton's 2006 book the Biology of Belief .
Lipton is a credentialed scientist himself (PhD cell biology researcher at Stanford School of Medicine), but he gets hand-wavy about concepts like epigenetics and quantum entanglement and leaves himself vulnerable to attack from mainstream skeptics.
But it's only by applying the principles he describes that I've been able to make the progress I've made over the past 6-7 years.
For more info, you're welcome to contact me directly - email in bio.