Church, D., Yount, G., & Brooks, A. J. (2012). The effect of emotional freedom techniques on stress biochemistry: a randomized controlled trial. The Journal of Nervous and Mental Disease, 200(10), 891-896.
This study examined the changes in cortisol levels and psychological distress symptoms of 83 nonclinical subjects receiving a single hourlong intervention. Subjects were randomly assigned to either an emotional freedom technique (EFT) group, a psychotherapy group receiving a supportive interviews (SI), or a no treatment (NT) group. Salivary cortisol assays were performed immediately before and 30 minutes after the intervention. Psychological distress symptoms were assessed using the symptom assessment-45. The EFT group showed statistically significant improvements in anxiety (−58.34%, p < 0.05), depression (−49.33%, p < 0.002), the overall severity of symptoms (−50.5%, p < 0.001), and symptom breadth (−41.93%, p < 0.001). The EFT group experienced a significant decrease in cortisol level (−24.39%; SE, 2.62) compared with the decrease observed in the SI (−14.25%; SE, 2.61) and NT (−14.44%; SE, 2.67) groups (p < 0.03). The decrease in cortisol levels in the EFT group mirrored the observed improvement in psychological distress.