Paraphilic Sexual Offenders Do Not Differ From Control Subjects With Respect to Dopamine- and Serotonin-Related Genetic Polymorphisms

Serotonin system-associated genetic and epigenetic changes in pedophilia and child sexual offending

Numerous studies have shown associations between anomalies of the serotonergic system and impulsive behavior, depression, or traumatic life events. However, it is currently unknown, whether pedophilia or child sexual offending (CSO) is also related to alterations of the serotonergic system. Using a two by two factorial paradigm within a multisite consortium (NeMUP*) study cohort, we analyzed whether the SLC6A4-linked polymorphic region (SLC6A4LPR) or the SLC6A4 (transporter) and HTR3A (receptor) promotor methylation rates differed with regard to a pedophilic preference and/or child sexual offending. Methylation rates of HTR3A showed significant differences between child sexual offenders and non-offenders, with child sexual offenders showing lower methylation rates. Moreover, HTR3A methylation rates showed significant negative correlations with the Child Trauma Questionnaire (CTQ) subscale "sexual violence", and the number of sexual offenses committed. Interestingly, we also found pedophilia-related alterations in 5HT3A as well as SLC6A4 methylation rates. For HTR3A we detected significant higher methylation rates in subjects with a pedophilic sexual preference, whereas for SLC6A4 methylation rates were reduced, indicating a possible downregulation of the serotonergic system in total. Although there were no significant group differences concerning the SLC6A4LPR, we found a significant correlation of the SLC6A4 methylation rate with this polymorphism in pedophilia. The present study suggests an involvement of epigenetic alterations of the serotonergic system in pedophilia and child sexual offending as well as own experience of sexual violence. While such an environmental factor may account for the epigenetic changes seen in child sexual offending, this was not seen in pedophilia. These findings will hopefully inspire further research in this underinvestigated field which should aim at validating and extending these initial results.

The World Federation of Societies of Biological Psychiatry (WFSBP) 2020 guidelines for the pharmacological treatment of paraphilic disorders

Objectives: The primary aim of these guidelines is to evaluate the role of pharmacological agents in the treatment and management of patients with paraphilic disorders, with a focus on the treatment of adult males. Because such treatments are not delivered in isolation, the role of specific psychotherapeutic interventions is also briefly covered. These guidelines are intended for use in clinical practice by clinicians who diagnose and treat patients, including sexual offenders, with paraphilic disorders. The aim of these guidelines is to bring together different views on the appropriate treatment of paraphilic disorders from experts representing different countries in order to aid physicians in clinical decisions and to improve the quality of care.Methods: An extensive literature search was conducted using the English-language-literature indexed on MEDLINE/PubMed (1990-2018 for SSRIs) (1969-2018 for hormonal treatments), supplemented by other sources, including published reviews.Results: Each treatment recommendation was evaluated and discussed with respect to the strength of evidence for its efficacy, safety, tolerability, and feasibility. The type of medication used depends on the severity of the paraphilic disorder and the respective risk of behaviour endangering others. GnRH analogue treatment constitutes the most relevant treatment for patients with severe paraphilic disorders.Conclusions: An algorithm is proposed with different levels of treatment for different categories of paraphilic disorders accompanied by different risk levels.

Catechol-O-Methyltransferase Val158Met and brain-derived neurotrophic factor Val66Met gene polymorphisms in paraphilic sexual offenders

BACKGROUND

Child sexual abuse (CSA) is an important problem worldwide. The reason of sex abuse is considered as multifactorial. Genetic contribution reported by recent studies is a significant evidence for this pathologic behavior. Catechol-O-Methyltransferase (COMT) is an enzyme in the metabolic inactivation of catecholamine and substances containing catecholamines such as dopamine, epinephrine, and norepinephrine. COMT polymorphism causes functional changes in COMT enzyme activity. Brain-derived neurotrophic factor (BDNF) is a neurotrophic factor usually synthesized from central nervous system neurons. With the effect of BDNF, dopamine and serotonin play important roles on neurogenesis, survival, and synaptic plasticity.

AIM

This study aims to examine COMT Val158Met (rs4680) and BDNF Val66Met (rs6265) polymorphisms in CSA.

SETTINGS AND DESIGN

This was a case-control study.

MATERIALS AND METHODS

Seventy paraphilic child sexual abuser patients and seventy age- and gender-matched healthy controls participated in this study. COMT Val158Met and BDNF Val66Met polymorphisms were genotyped by real-time polymerase chain reaction assay.

RESULTS

COMT Val158Met genotype frequencies were determined as GG 31.4%, GA 45.7%, and AA 22.9% in patients; GG 24.3%, GA 45.7%, and AA 8.6% in controls; and exhibited a positive relationship between the groups (P = 0.018). BDNF Val66Met genotype frequencies were determined as GG 77.1%, GA 21.4%, and AA 1.4% in patients; GG 65.7%, GA 31.4%, AA 2.9% in controls; and no significant relationship was observed between the groups (P = 0.317).

CONCLUSIONS

This research investigated COMT (Val158Met) and BDNF (Val66Met) in paraphilic child sexual offenders. A positive relationship was found for COMT gene; however, no significant relation was observed for BDNF gene between paraphilic sexual offenders and controls.

Child sexual offenders show prenatal and epigenetic alterations of the androgen system

Child sexual offending (CSO) places a serious burden on society and medicine and pedophilia (P) is considered a major risk factor for CSO. The androgen system is closely linked to sexual development and behavior. This study assessed markers of prenatal brain androgenization, genetic parameters of androgen receptor function, epigenetic regulation, and peripheral hormones in a 2 × 2 factorial design comprising the factors Offense (yes/no) and Pedophilia (yes/no) in analyzing blood samples from 194 subjects (57 P+CSO, 45 P-CSO, 20 CSO-P, and 72 controls) matched for age and intelligence. Subjects also received a comprehensive clinical screening. Independent of their sexual preference, child sexual offenders showed signs of elevated prenatal androgen exposure compared with non-offending pedophiles and controls. The methylation status of the androgen receptor gene was also higher in child sexual offenders, indicating lower functionality of the testosterone system, accompanied by lower peripheral testosterone levels. In addition, there was an interaction effect on methylation levels between offense status and androgen receptor functionality. Notably, markers of prenatal androgenization and the methylation status of the androgen receptor gene were correlated with the total number of sexual offenses committed. This study demonstrates alterations of the androgen system on a prenatal, epigenetic, and endocrine level. None of the major findings was specific for pedophilia, but they were for CSO. The findings support theories of testosterone-linked abnormalities in early brain development in delinquent behavior and suggest possible interactions of testosterone receptor gene methylation and plasma testosterone with environmental factors.

Are There Any Biomarkers for Pedophilia and Sexual Child Abuse? A Review

The use of biomarkers in medicine is a common and valuable approach in several clinical fields. Understanding the relationship between measurable biological processes and clinical outcomes not only is indispensable in the face of understanding physiological processes in healthy as well as in diseased organisms but also for understanding and evaluating treatment effects. Therefore, also in the context of forensic psychiatry, biomarkers and their potentially beneficial effects are of growing interest. The objective of this review is to examine if there are biomarkers that may serve as a tool to support diagnostic process, treatment evaluation, and risk assessment of pedophilic individuals and child sexual offenders. In the first part, we present an overview of the current neurobiological, as well as physiological and psychophysiological approaches to characterize pedophilia and child sexual offending. Secondly, we discuss and evaluate the impact of these approaches on the development of biomarkers for diagnosis, therapy, and risk assessment in pedophilic subjects and child sexual offenders. We conclude that a lot of research has already enhanced our neurobiological knowledge about pedophilia and child sexual offending. Although there surely exist promising parameters and approaches, in our view currently none of these is ready yet to serve as a clinically applicable diagnostic, response, or predictive biomarker for pedophilia and child sexual offending. Therefore, further work remains to be done. The development of a composite diagnostic biomarker to assess deviant sexual interest, combining several measures like functional magnetic resonance imaging, electroencephalogram, eye tracking, and behavioral approaches seems to be most promising. A valid and reliable measurement of deviant sexual interest, insensitive to manipulations could significantly support clinical diagnostic process. Similarly, regarding therapy evaluation and risk assessment, a composite biomarker to assess inhibitory control functions seems to be promising. Furthermore, the application of the Research Domain Criteria-approach, a new approach for investigating and classifying mental disorders, offers the possibility to take research to a new level.