We placed this question for feedback by various experts at linkedin.com to know the psychological effects of yoga therapy and received their feedbacks compiled below.
Many experts (Veena G. & Lee M) suggested for Kundalini Yoga Meditations by Shannahoff Khalsa (yogi Bhajan) for Psychiatric Disorders. I personally saw the good results in research studies conducted by Khalsa. One expert recommended one book 'Kundalini Yoga' by Yogi Bhajan is wonderful book.
In a nutshell, they suggested that deep breathing slowly through the nose calms the mind & create peace in your mind - practicing deep breathing & bringing positive energy to your brain & with exhale releasing the negativity out, causing positive psychological effect of yoga therapy on the mind.
One member, Veena U, commented that there's some ground-breaking research by Chris Streeter from Boston University School of Medicine. In 2007 her and her team did an MRI study looking at levels of GABA (an inhibitory neurotransmitter in the brain, low levels of which are associated with anxiety) and found that GABA levels increased in the brain after 1 hours yoga practise. She followed this up in 2010 and found increased GABA levels in comparison with 1 hours reading and 1 hours walking.
The work of Patricia Gerbarg and Richard Brown (and Streeter) and Luciano Bernardi have theorised about the mechanisms by which self-regulation can occur when modulating breath.
She posted links to some of these papers:
http://www.ncbi.nlm.nih.gov/pubmed/22365651http://www.ncbi.nlm.nih.gov/pubmed/17532734http://www.ncbi.nlm.nih.gov/pubmed/20722471
The link where the feedbacks on the psychological effects of yoga therapy are mentioned is http://www.linkedin.com/groupAnswers?viewQuestionAndAnswers=&discussionID=101399483&gid=3784793&commentID=80621779&trk=view_disc&ut=2StcO7eKTD1Rg1
