Karrasch, S., Matits, L., Bongartz, W., Mavioğlu, R. N., Gumpp, A. M, Mack, M., Tumani, V., Behnke, A., Steinacker, J. M., & Kolassa, I. T., (2023)
Biological Psychology, 178 https://doi.org/10.1016/j.biopsycho.2023.108527
The article examines the relaxation hypnosis effects on chronic stress reaction in 44 mild or highly hypnotizable individuals (measured with Harvard Group Scale), who suffered from chronic stress. Half of them got 20 minutes of hypnotic suggestions, and the control group saw a 20-minute documentary film. The blood samples were examined before and after hypnosis. The erythrocytes number and related parameters, thrombocytes number also significantly declined as a result of the suggestions. The explanation is not clear, but there’s a possibility, that these changes are the results of the increase in plasma volume and vasodilation caused by the suggestions. These effects occurred after one hypnosis session. The stress has drastic effects on the blood particles through epinephrine, e.g. increasing the leukocytes number in the peripheral blood flow (Bischoff, 2016 in Karrash Matits, 2023) and in long term decreased leukocytes number. (Al-Hatamleh et al., 2019; Maydych et al., 2017 in Karash, 2023) Mental stress also rises the number of thrombocytes (Kop, 1999., von Kanel, 2003) and exerts the effect in 10 minutes (Jern, 1989 in Karrash, 2023).
After hypnosis the level of erythrocytes and thrombocytes decreased; plasma volume and a portion of immature thrombocytes increased. The background mechanism is not clear yet but is possibly related to thrombopoietin according to Saxonhouse & Sola-Visner (2012) and the dominant parasympathetic effect (Bernardi et al., 2017) which caused vasodilation.
This study didn’t find any changes in the number of the leukocytes during the 20-minute-long hypnotic session. The explanation could be the duration of the intervention. Bogarts (1993) found decreased leukocyte number after a 30-minute hypnosis session. More research is needed to understand this discrepancy.