The following clinical study with American veterans suffering PTSD illustrates just how powerful these techniques can be. 

Psychological trauma symptom improvement in veterans using EFT (Emotional Freedom Techniques): A randomized controlled trial.

Dawson Church, PhD, Foundation for Epigenetic Medicine, Crystal Hawk, MEd, Therapeutic Touch Network of Ontario, Audrey Brooks, PhD, Psychology Dept., University of Arizona at Tucson. 
Olli Toukolehto, MD, Walter Reed National Military Medical Center
Maria Wren, LCSW, Veterans Administration Connecticutt Newington Campus, Ingrid Dinter, Healing Now, Hopkinton, New Hampshire, Phyllis Stein, PhD, Washington University School of Medicine.

Abstract
This study examined the effect of EFT, a brief exposure therapy combining cognitive and somatic elements, on posttraumatic stress disorder (PTSD) and psychological distress symptoms in veterans receiving mental health services. Veterans meeting the clinical criteria for PTSD were randomized to EFT (n = 30) or wait list (n = 29). The EFT intervention consisted of 6 hour-long EFT coaching sessions concurrent with standard care. The wait list and EFT groups were compared pre- and post test (at 1 month for the WL group, after 6 sessions for EFT group). 

EFT subjects had significantly reduced psychological distress (p < .0012) and PTSD symptom levels (p < .0001) post test.  In addition, 90% of the EFT group no longer met PTSD clinical criteria, compared with 4% in the wait list.  Following the wait period, WL subjects received EFT.  60% no longer met PTSD clinical criteria after 3 sessions. This increased to 86% after 6 sessions for the 49 subjects who ultimately received EFT and remained at 86% at 3-months and 80% at 6-months. The results are consistent with other published reports showing EFTs efficacy at treating PTSD and co-morbid symptoms and its [EFT’s]long-term effects.

Citation (APA Style): Church, D., Hawk, C., Brooks, A. J., Toukolehto, O., Wren, M., Dinter, I., & Stein, P. (2013) Psychological trauma symptom improvement in veterans using EFT (Emotional Freedom Techniques): A randomized controlled trial. Journal of Nervous and Mental Disease, 201, 153-160.