Exploratory association study between catechol-O-methyltransferase (COMT) high/low enzyme activity polymorphism and hypnotizability

Only recently have studies of electrocortical activity, event-related potentials, and regional cerebral blood flow begun to shed light on the anatomical and neurobiological underpinnings of hypnosis. Since twin studies show a significant heritable component for hypnotizability, we were prompted to examine the role of a common, functional polymorphism in contributing to individual differences in hypnotizability. A group of 109 subjects (51 male, 59 female) were administered three psychological instruments and tested for the high/low enzyme activity COMT val→met polymorphism. We observed a significant correlation between hypnotizability measured by the Stanford Hypnotic Susceptibility Scale (SHSS:C), ability to partition attention (Differential Attentional Processes Inventory or DAPI), and absorptive capacities (Tellegen Absorption Scale or TAS). The effect of COMT on the various dependent variables was initially examined by multivariate analysis that corrects for multiple testing. The dependent variables were SHSS:C hypnotizability scores, four attentional subscales of the DAPI, and TAS total score grouped by the COMT genotype (val/val, val/met, met/ met) as the independent variable. Hotelling's Trace statistic was significant when scores were grouped by the COMT genotype (Hotelling's T² = 1.88, P = 0.04). Post-hoc testing using the Bonferroni correction shows that the only significant difference is between the val/met vs. the val/val COMT genotypes on hypnotizability. This association was significant for men but not for women. As for all case-control studies, these results need to be interpreted cautiously and require replication.(C) 2000 Wiley-Liss, Inc.