Predicting trait-like individual differences in fear of pain in the healthy state using gray matter volume.

Fear of pain (FOP) can be considered as a product of evolution from overstated negative interpretations of pain and sometimes may cause more damage than the actual pain itself. While trait-like measures of FOP have emerged as predictors for the inception and development of chronic pain, its neural underpinnings are not well understood. To investigate the relationship between gray matter volumes (GMV) and trait-like individual differences in FOP, we analyzed structural magnetic resonance imaging data in a sample of healthy young adults. Regression analysis results showed that individuals with higher FOP scores displayed higher GMV in brain regions important for the regulation of pain and fear. These brain areas include the pregenual anterior cingulate cortex (ACC), the anterior part of the dorsal ACC, the dorsomedial prefrontal cortex, and the adjacent pre-supplementary motor area. Furthermore, cross-validation analysis confirmed that the identified regional GMV offered a reliable neural signature of trait-like FOP. Our findings shed more light on the neuroanatomical architecture of FOP in currently pain-free people, which may be helpful to guide early interventions to prevent FOP from becoming chronic.