Multimodal neuroimaging measures and intelligence influence pedophile child sexual offense behavior

Pedophilia is a heterogeneous disorder for which the neurobiological correlates are not well established. In particular, there are no biological markers identifying individuals with high risk to commit child sexual offense (CSO). Pedophiles with CSO (P+CSO; N = 73), pedophiles without CSO (P-CSO; N = 77), and non-pedophilic controls (NPC; N = 133) were assessed using multimodal structural neuroimaging measures including: cortical thickness (CT), surface area (SA), and white matter fractional anisotropy (FA), as well as full scale IQ (FSIQ) performance. Cortex-wise mediation analyses were used to assess the relationships among brain structure, FSIQ and CSO behavior. Lower FSIQ performance was strongly predict with P+CSO (Wald Chi2 = 13.0, p = 3.1 × 10-5). P+CSO had lower CT in the right motor cortex and pronounced reductions in SA spanning the bilateral frontal, temporal, cingulate, and insular regions (PFWE-corrected < 0.05). P+CSO also had lower FA particularly in the corpus callosum (PFWE-corrected < 0.05). The relationship between SA and P+CSO was significantly mediated by FSIQ, particularly in the prefrontal and anterior insular cortices (PFWE-corrected < 0.05). Within P+CSO, left prefrontal and right anterior cingulate SA negatively correlated with number of CSOs (PFWE-corrected < 0.05). This study demonstrates converging neurobiological findings in which P+CSO had lower FSIQ performance, reduced CT, reduced SA, and reduced FA, compared to P-CSO as well as NPC. Further, FSIQ potentially mediates abuse by pedophiles via aberrant SA, whereas the CT and FA associations were independent of FSIQ differences. These findings suggest aberrant neuroanatomy and lower intelligence as a potential core feature underlying child sexual abuse behavior by pedophiles.