The neurochemistry of hypnotic suggestion
Published in American Journal of Clinical Hypnosis, 2021
David J. Acunzo, David A. Oakley, Devin B. Terhune
Multiple reports imply that elevated GABA produces increased suggestibility. However, these data come from studies that lacked placebo-controlled trials and robust measures of suggestibility and thus should be considered preliminary. Early research suggested that amobarbital, a GABAA receptor agonist, increases suggestibility (Eysenck & Rees, 1945). Recent research has highlighted how the abuse of benzodiazepines, which include a large number of sedative GABAA agonists, produces automatism amnesia where individuals will perform seemingly automatic behaviors and display elevated suggestibility often followed by anterograde amnesia (Goullé & Anger, 2004; Marc et al., 2000). Benzodiazepines have also been cited as increasing suggestibility in the context of narcotherapy in functional neurological disorder (Rosebush & Mazurek, 2011). Gamma hydroxybutyric acid, a GABAB agonist used in the treatment of narcolepsy and as an anesthetic agent, has similarly been reported to increase suggestibility (e.g., Bismuth, Dally, & Borron, 1997). These encouraging, albeit preliminary, results point to a clear need to more rigorously assess the impact of GABA agonism on suggestibility, including an assessment of mediating factors to distinguish between competing interpretations of these results.