The following links provide articles and research material related to the application and effectiveness of hypnosis and hypnotherapy.
Insights Imaging 12, 83 (2021). https://doi.org/10.1186/s13244-021-01020-7
EEG technology now allows us to record brainwave activity during hypnosis. You can see here several snapshots of brainwave activity whilst experiencing various hypnotic phenomena.
The Efficacy of Hypnosis as a Treatment for Anxiety: A Meta-Analysis
International Journal of Clinical and Experimental Hypnosis, 67:3, 336-363, DOI: 10.1080/00207144.2019.1613863
The effect of mental stress on the non-dipolar components of the T wave: modulation by hypnosis
Psychosomatic Medicine 2005 May-Jun;67(3):376-83
Single-session hypnotherapy for smoking cessation
European Journal of General Practice June 2002, Volume 8