Toward a Neurodevelopmental Understanding of Pedophilia

Pedohebephilia and Perceived Non-coercive Childhood Sexual Experiences: Two Non-matched Case-Control Studies

Research on the link between childhood sexual abuse experiences (CSAE) and pedohebephilia is limited by its focus on events that the respondents rate as abusive. We asked 199 German-speaking (Study 1) and 632 English-speaking (Study 2) men with and without self-reported pedohebephilia to complete the Childhood Trauma Questionnaire (CTQ) and scales to assess perceived non-coercive childhood sexual experiences with adults (PNCSE-A), and peers (PNCSE-P, only Study 2). A substantial number of participants with PNCSE-A disagreed with all items of the CTQ Sexual Abuse subscale (e.g., 35% and 26% of pedohebephilic men in Studies 1 and 2, 38% of teleiophilic men in Study 2). While pedohebephilic men reported more CSAE than teleiophilic men, the effects for PNCSE-A did not consistently point in the expected direction. In Study 2, conviction status for sexual offenses among pedohebephilic men was linked to higher rates of CSAE, PNCSE-A, PNCSE-P, physical neglect, and physical abuse. Pedohebephilic men in Study 2 also reported more PNCSE-P than teleiophilic men. Our results highlight the importance of assessing different (positive or neutral) perceptions of CSAE. Better controlled designs (e.g., matched case-control studies) are needed to substantiate whether and how perceived non-coercive childhood sexual experiences relate to pedohebephilia and sexual offending.

Patterns of risk-Using machine learning and structural neuroimaging to identify pedophilic offenders

Background

Child sexual abuse (CSA) has become a focal point for lawmakers, law enforcement, and mental health professionals. With high prevalence rates around the world and far-reaching, often chronic, individual, and societal implications, CSA and its leading risk factor, pedophilia, have been well investigated. This has led to a wide range of clinical tools and actuarial instruments for diagnosis and risk assessment regarding CSA. However, the neurobiological underpinnings of pedosexual behavior, specifically regarding hands-on pedophilic offenders (PO), remain elusive. Such biomarkers for PO individuals could potentially improve the early detection of high-risk PO individuals and enhance efforts to prevent future CSA.

Aim

To use machine learning and MRI data to identify PO individuals.

Methods

From a single-center male cohort of 14 PO individuals and 15 matched healthy control (HC) individuals, we acquired diffusion tensor imaging data (anisotropy, diffusivity, and fiber tracking) in literature-based regions of interest (prefrontal cortex, anterior cingulate cortex, amygdala, and corpus callosum). We trained a linear support vector machine to discriminate between PO and HC individuals using these WM microstructure data. Post hoc, we investigated the PO model decision scores with respect to sociodemographic (age, education, and IQ) and forensic characteristics (psychopathy, sexual deviance, and future risk of sexual violence) in the PO subpopulation. We assessed model specificity in an external cohort of 53 HC individuals.

Results

The classifier discriminated PO from HC individuals with a balanced accuracy of 75.5% (sensitivity = 64.3%, specificity = 86.7%, P ₅₀₀₀ = 0.018) and an out-of-sample specificity to correctly identify HC individuals of 94.3%. The predictive brain pattern contained bilateral fractional anisotropy in the anterior cingulate cortex, diffusivity in the left amygdala, and structural prefrontal cortex-amygdala connectivity in both hemispheres. This brain pattern was associated with the number of previous child victims, the current stance on sexuality, and the professionally assessed risk of future sexual violent reoffending.

Conclusion

Aberrant white matter microstructure in the prefronto-temporo-limbic circuit could be a potential neurobiological correlate for PO individuals at high-risk of reoffending with CSA. Although preliminary and exploratory at this point, our findings highlight the general potential of MRI-based biomarkers and particularly WM microstructure patterns for future CSA risk assessment and preventive efforts.

Neurodevelopmental Differences, Pedohebephilia, and Sexual Offending: Findings from Two Online Surveys

The neurodevelopmental theory of pedohebephilia states that sexual interests in children arise from early neurodevelopmental perturbations, as, for example, evidenced by increased non-right-handedness, more childhood head injuries, and reduced intelligence and height. As corroborating evidence largely rests on samples of convicted men, we conducted online surveys among German-speaking (Study 1, N = 199) and English-speaking men (Study 2, N = 632), specifically targeting community members with pedohebephilic or teleiophilic interests. Although we detected theoretically meaningful sexual interest patterns in an embedded viewing time task, we could not detect expected neurodevelopmental differences between teleiophilic and pedohebephilic men in either of the two studies. Strikingly, pedohebephilic men who reported convictions for sexual offenses emerged as shorter and less intelligent than pedohebephilic men without convictions in Study 2. While elucidating possible third variable confounds, results have to be interpreted cautiously because of the methodological problems inherent to non-matched case control designs.

Brain structure and clinical profile point to neurodevelopmental factors involved in pedophilic disorder

OBJECTIVE

Pedophilic disorder (PD) is characterized bypersistent, intense sexual attraction to prepubertal children that the individual has acted on, or causes marked distress or interpersonal difficulty. Although prior research suggests that PD has neurodevelopmental underpinnings, the evidence remains sparse. To aid the understanding of etiology and treatment development, we quantified neurobiological and clinical correlates of PD.

METHOD

We compared 55 self-referred, help-seeking, non-forensic male patients with DSM-5 PD with 57 age-matched, healthy male controls (HC) on clinical, neuropsychological, and structural brain imaging measures (cortical thickness and surface area, subcortical and white matter volumes). Structural brain measures were related to markers for aberrant neurodevelopment including IQ, and the 2nd to 4th digit ratio (2D:4D).

RESULTS

PD was associated with psychiatric disorder comorbidity and ADHD and autism spectrum disorder symptoms. PD patients had lower total IQ than HC. PD individuals exhibited cortical surface area abnormalities in regions belonging to the brain's default mode network and showed abnormal volume of white matter underlying those regions. PD subjects had smaller hippocampi and nuclei accumbens than HC. Findings were not related to history of child-related sexual offending. IQ correlated negatively with global expression of PD-related brain features and 2D:4D correlated with surface area in PD.

CONCLUSIONS

In the largest single-center study to date, we delineate psychiatric comorbidity, neurobiological and cognitive correlates of PD. Our morphometric findings, their associations with markers of aberrant neurodevelopment, and psychiatric comorbidities suggest that neurodevelopmental mechanisms are involved in PD. The findings may need consideration in future development of clinical management of PD patients.

The Neurology of Acquired Pedophilia

The clinicoanatomic cases of acquired pedophilia that have been published in the medical and forensic literature up to 2019 are reviewed. Twenty-two cases fit our inclusion criteria. All but one were men, and in only one case the injury was localized to the left hemisphere. Hypersexuality was present in 18 cases. The damaged areas fell within the frontotemporoinsular cortices and related subcortical nuclei; however, the anterior hypothalamus was spared. Damage to parts of the right frontotemporoinsular lobes with sparing of the anterior hypothalamus seems to be critical for the emergence of acquired pedophilia.