Vagus nerve stimulation and food cravings: A response to Gibson and Mohiyeddini

Recently, we conducted the first study to date on the effects of VNS on food cravings among depressed adults and concluded that VNS activation appears to acutely alter food cravings in depressed adults. Interestingly, we found that VNS device activation was associated with acute increases in cravings in some participants, and decreases in others. We then implemented exploratory regression analysis to determine some potential variables that accounted for this variability in VNS-related changes in food cravings for future studies to consider for further study. Gibson and Mohiyeddini critically examined this paper and despite acknowledging that the concept is interesting, they suggest that our design, analysis and interpretation should be reconsidered. Specifically, they had concerns about the validity of our dependent measure, the way in which we operationalized alteration in cravings, and possible problems with our regression analysis. However, a review of the methods commonly employed in the literature for assessing acute changes in cravings supports the validity of our cravings measure. We believe that our procedures for extracting VNS-related alterations in food cravings, while imperfect, strike a nice balance between the difficult challenges of research design regarding acute VNS-related behavioral changes and meaningful inference. Additionally, logical flaws and unfounded speculation regarding the assumptions of our regression analyses led Gibson and Mohiyeddini to make faulty assertions regarding potential problems with our exploratory model. We contend that the inferences and conclusions we reached in the original paper are sound.