Relaxation Response in Stressed Volunteers: Psychometric Tests and Neurotrophin Changes in Biological Fluids

Author: Miriam Zappella1,2, Filippo Biamonte3, Bijorn Omar Balzamino4, Rocco Manieri5, Magdalena Cortes6,7, Daniela Santucci8, Enrico Di Stasio3,5, Maurizio Rizzuto1, Alessandra Micera4
1 Department of Psychology, Salesian University of Rome, Rome, Italy.
2 Department of Neuroscience, IRCCS Children's Hospital Bambino Gesù, Rome, Italy.
3 Department of Basic Biotechnological Sciences, Intensive and Perioperative Clinics, Catholic University of the Sacred Heart, Rome, Italy.
4 Research and Development Laboratory for Biochemical, Molecular and Cellular Applications in Ophthalmological Sciences; IRCCS - Fondazione Bietti, Rome, Italy.
5 Department of Laboratory and Infectivological Sciences, UOC Chemistry, Biochemistry and Molecular Biology Clinic, Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome, Italy.
6 Hebrew Hospital Rome Ophthalmology Department, Rome, Italy.
7 Prevention and Health Care Department, Campus Bio Medico University, Rome, Italy.
8 Cellular Biology and Neurosciences, Istituto Superiore di Sanita, Rome, Italy.
Conference/Journal: Front Psychiatry
Date published: 2021 Jun 17
Other: Volume ID: 12 , Pages: 655453 , Special Notes: doi: 10.3389/fpsyt.2021.655453. , Word Count: 359

Background: To evaluate the beneficial effects of relaxation response (RR) training in adult stressed subjects by evaluating the psychometric response recorded at relaxation session. Cortisol as well as nerve growth factor (NGF) and brain derived neurotrophic factor (BDNF) mediators were quantified in both saliva and tears, and their levels were related to each other and to the psychometric response. Methods: Stressed subjects (n = 23; 10M/13F; age range 21-53 years old) were voluntarily enrolled in the study. RR training sessions were carried out for 2 months, 1 day per week, at the same time (3-5 p.m.). Two different psychological questionnaires, the Perceived Stress Scale-10 (PSS-10) and the Beck Depression Inventory - Short Form (BDI-SF) and Ocular Surface Disease Index (OSDI) tests, were administered before each session. Saliva and tears were sampled for cortisol (EIA), NGF (ELISA), and BDNF (ELISA) quantifications. Questionnaires' data were analyzed and compared to biochemical ones. Results: All subjects reported beneficial effects from training. RR significantly reduced the psychological stress indexes (p = 0.039 for PSS-10 and p = 0.001 for BDI-SF). Specifically, RR training lowered the perception of Perceived Helplessness (items 1, 3, 10; p < 0.05) in PSS-10 and increased the Perceived Self-Efficacy (p < 0.05). OSDI score was in the normal range (0-25). Biochemically, a decrease in cortisol, a trend to a decrease in NGF, and an increase in BDNF levels were observed in saliva samples after RR treatment. Furthermore, a trend to a decrease in NGF and an increase in BDNF were quantified in tear samples. A correlation between PSS-10 total score and saliva NGF variation (%) as well as between BDI-SF total score and BDNF tear levels were also observed. Conclusion: RR training appeared useful to lowering psychological, mental, and physical stress, as supported by both psychological total and single scores. The finding on biochemical levels of BDNF in saliva and tears are sustained by previous studies while those of NGF require further investigation. Overall, these data on a small population highlight the potential use of RR training and potential neurotrophic changes in biological fluids, in stressed volunteers.

Keywords: PSS-10 perceived stress scale; brain derived neurotrophic factor; nerve growth factor; relaxation response meditation technique; saliva analysis; tears analysis.

PMID: 34220571 PMCID: PMC8247444 DOI: 10.3389/fpsyt.2021.655453