Association between Anterior Cingulate Neurochemical Concentration and Individual Differences in Hypnotizability

Hypnotizability, a stable trait in adulthood, is linked to the concentration of the neurotransmitter GABA in the anterior cingulate cortex (ACC). In healthy individuals, higher ACC GABA levels were positively associated with higher hypnotizability scores measured by the Hypnotic Induction Profile. An exploratory analysis also found a negative relationship between glutamate levels and the absorption and imaginative involvement subscale of the Dissociative Experiences Scale. These findings suggest a neurobiological basis for individual differences in hypnotic responsiveness, which may help explain variability in treatment outcomes for hypnosis-based psychotherapies.

Study at a glance

Abstract

Hypnosis is the oldest form of Western psychotherapy and a powerful evidence-based treatment for numerous disorders. Hypnotizability is variable between individuals; however, it is a stable trait throughout adulthood, suggesting that neurophysiological factors may underlie hypnotic responsiveness. One brain region of particular interest in functional neuroimaging studies of hypnotizability is the anterior cingulate cortex (ACC). Here, we examined the relationships between the neurochemicals, GABA, and glutamate, in the ACC and hypnotizability in healthy individuals. Participants underwent a magnetic resonance imaging (MRI) session, whereby T1-weighted anatomical and MEGA-PRESS spectroscopy scans were acquired. Voxel placement over the ACC was guided by a quantitative meta-analysis of functional neuroimaging studies of hypnosis. Hypnotizability was assessed using the Hypnotic Induction Profile (HIP), and self-report questionnaires to assess absorption (TAS), dissociation (DES), and negative affect were completed. ACC GABA concentration was positively associated with HIP scores such that the higher the GABA concentration, the more hypnotizable an individual. An exploratory analysis of questionnaire subscales revealed a negative relationship between glutamate and the absorption and imaginative involvement subscale of the DES. These results provide a putative neurobiological basis for individual differences in hypnotizability and can inform our understanding of treatment response to this growing psychotherapeutic tool.