Pedophilia is linked to reduced activation in hypothalamus and lateral prefrontal cortex during visual erotic stimulation.

BACKGROUND: Although pedophilia is of high public concern, little is known about underlying neural mechanisms. Although pedophilic patients are sexually attracted to prepubescent children, they show no sexual interest toward adults. This study aimed to investigate the neural correlates of deficits of sexual and emotional arousal in pedophiles. METHODS: Thirteen pedophilic patients and 14 healthy control subjects were tested for differential neural activity during visual stimulation with emotional and erotic pictures with functional magnetic resonance imaging. RESULTS: Regions showing differential activations during the erotic condition comprised the hypothalamus, the periaqueductal gray, and dorsolateral prefrontal cortex, the latter correlating with a clinical measure. Alterations of emotional processing concerned the amygdala-hippocampus and dorsomedial prefrontal cortex. CONCLUSIONS: Hypothesized regions relevant for processing of erotic stimuli in healthy individuals showed reduced activations during visual erotic stimulation in pedophilic patients. This suggests an impaired recruitment of key structures that might contribute to an altered sexual interest of these patients toward adults.     

Retrospective self-reports of childhood accidents causing unconsciousness in phallometrically diagnosed pedophiles

The present study investigated whether head injuries in childhood might increase the risk of pedophilia in males. The subjects were 1206 patients referred to a clinical sexology service for assessment of their erotic preferences. These were classified, on the basis of phallometric test results, as pedophilic (n = 413) or nonpedophilic (n = 793). Information regarding early head injuries, other signs of possible neurodevelopmental problems, and parental histories of psychiatric treatment were collected with self-administered questionnaires. The results showed that childhood accidents that resulted in unconsciousness were associated with pedophilia and with lower levels of intelligence and education. These associations were statistically significant for accidents that occurred before the age of 6, but not for accidents that occurred between the ages of 6 and 12. These results are compatible with the hypothesis that neurodevelopmental perturbations in early childhood may increase the risk of pedophilia. They are also, however, compatible with the alternative explanation that prior neurodevelopmental problems lead to accident-proneness and head injury, on the one hand, and to pedophilia, on the other, and that head injury has no causal influence on pedophilia. A secondary finding was that the pedophiles were more likely to report that their mothers had undergone psychiatric treatment. This finding suggests that pedophilia may be influenced by genetic factors, which are manifested in women as an increased risk of psychiatric problems, and in their sons, as an increased risk of erotic interest in children.     

Handedness in Pedophilia and Hebephilia

A sample of 404 adult men underwent assessment following illegal or clinically significant sexual behaviors or interests. Patients’ assessments included: administration of a modified version of the Edinburgh Handedness Inventory; recording of patients’ phallometric (penile) responses to erotic stimuli depicting adults, pubescent children, and prepubescent children of both sexes; and a tabulation of the numbers of patients’ victims, ages 0–11, 12–14, 15–16, and 17 and older, of both sexes. In Study 1, patients’ right-handedness scores correlated negatively with their phallometric responses to stimuli depicting prepubescent children and positively with stimuli depicting adults, replicating the pattern described in a previous report (Cantor et al., 2004). Unlike the previous study, however, patients’ handedness scores did not significantly correlate with their numbers of prepubescent victims. To explore this discrepancy, Study 2 combined the patients from this replication sample with those in the previously reported sample, categorizing them by the sex and age group of greatest erotic interest to them. The odds of non-right-handedness in men offending predominantly against prepubescent children were approximately two-fold higher than that in men offending predominantly against adults and three-fold higher after eliminating those men with intrafamilial (i.e., incest) offenses. Handedness differences between men erotically interested in males versus females were not statistically significant. These results indicate that the rates of non-right-handedness in pedophilia are much larger than previously suggested and are comparable to the rates observed in pervasive developmental disorders, such as autism, suggesting a neurological component to the development of pedophilia and hebephilia.     

Leuprolide Acetate Suppresses Pedophilic Urges and Arousability

Cognitive–behavioral psychotherapy was compared with cognitive–behavioral psychotherapy augmented by leuprolide acetate (LA) for suppression of pedophilic behavior. Five male pedophiles (M age, 50 years; range, 36–58) were administered LA by Depo injection for 12 months, followed by saline placebo for 12 months. Testosterone levels, sexual interest preference by visual reaction time (Abel Assessment), penile tumescence (Monarch Penile Plethysmography, PPG), as well as strong sexual urges toward children and masturbatory frequency involving thoughts of children (polygraph), were measured every 3 months. On LA, testosterone decreased to castrate levels. Penile tumescence was significantly suppressed compared with baseline, but sufficient response remained to detect pedophilic interest. Pedophilic interest was also detected by visual reaction times. When asked about having pedophilic urges and masturbating to thoughts of children, all subjects self-reported a decrease. Polygraph responses indicated subjects were not deceptive. On placebo, testosterone and physiologic arousal eventually rose to baseline. As noted by polygraph, at baseline and on placebo, subjects were deceptive regarding increased pedophilic urges and masturbatory frequency. Interest preference, as measured by Abel Assessment and Monarch PPG, was generally unchanged throughout the study. Cognitive–behavioral psychotherapy augmented with LA significantly reduced pedophilic fantasies, urges, and masturbation; however, pedophilic interest did not change during 1 year of therapy. Deceptive responses by polygraph suggested that self-report was unreliable. Follow-up utilizing objective measures is essential for monitoring efficacy of treatment in pedophilia. Our study supports the premise that suppression of pedophilic behavior is possible. LA may augment cognitive–behavioral psychotherapy and help break the sequence leading to a re-offense.     

Self-Reported Head Injuries Before and After Age 13 in Pedophilic and Nonpedophilic Men Referred for Clinical Assessment

Previous research has found that pedophilic men referred for clinical assessment of their sexual behavior are more likely to report that they suffered head injuries before their 13th birthday than are nonpedophilic men referred for the same purpose. This study investigated whether pedophilic patients are also more likely to report head injuries after their 13th birthday. The 685 participants represented all patients with usable data from a consecutive series of men referred to a clinical laboratory specializing in phallometric assessment of erotic preferences. In addition to phallometric testing, participants were administered a brief neuropsychological test battery and a companion interview, which included questions on head injury, drug abuse, and childhood diagnosis of attention-deficit/hyperactivity disorder. The results showed that the pedophilic patients reported more head injuries before age 13 than did the nonpedophilic patients, but they did not report more head injuries after age 13. The association between pedophilia and childhood head injuries could mean either that subtle brain damage after birth increases a boy's risk of pedophilia, or that neurodevelopmental problems before birth increase a boy's accident-proneness along with his risk of pedophilia. Additional analyses showed that self-reported head injuries before age 13 were associated with attentional problems and with left-handedness; in contrast, head injuries after age 13 were associated with drug abuse and promiscuity. These analyses suggest that, among patients with primary presenting complaints of sexual rather than cognitive problems, childhood head injuries cluster with neuropsychological phenomena, whereas later head injuries cluster with lifestyle variables.     

Sexual arousal as a function of physiological and cognitive variables in a sexual offender population

Physiological and cognitive variables may compromise the physiological assessment of sexual arousal, particularly in forensic settings. Thus, the effects of physiological and cognitive variables as potential moderators need investigation with respect to physiological measures of sexual arousal. Penile erection, demographic, and psychometric data were analyzed among 169 inpatient adult male sexual offenders. The hypotheses that (i) sexual arousability would be inversely related to age and (ii) subjects who were able to cognitively inhibit their sexual arousal would exhibit lower levels of pedophilic arousal than subjects who were unable to inhibit arousal were supported. Subject age did not interact with inhibition ability. Age and the presence of inhibitory ability appear to be arousability variables in that these variables mediate both deviant and nondeviant arousal.     

Discriminant analysis of a sexual-functioning inventory with intrafamilial and extrafamilial child molesters

Several suggestions have been offered by clinicians who work with sex offenders concerning etiological distinctions between incest offenders and extrafamilial child molesters. In this study we hypothesized that nonincestuous child molesters would have more sexual problems in general than would incestuous offenders. Ninety-five incest offenders and 127 nonincestuous child molesters were administered the Derogatis Sexual Functioning Inventory (DSFI), a self-report instrument. On the global Sexual Functioning Index the total sample of child molesters scored below the first percentile compared to the normative sample. In a direct discriminant analysis of the 10 subscales, satisfaction, fantasy, and experience were the principle variables discriminating between incestuous and nonincestuous offenders. Incest offenders were higher on experience and satisfaction and lower on fantasy. However, the discriminant analysis failed to yield clinically relevant distinctions between the sexual problems of extrafamilial and intrafamilial child molesters. DSFI scores for both groups indicated that their overall level of sexual functioning is poor relative to the general population.     

Pubertal Age in Homosexual and Heterosexual Sexual Offenders Against Children,Pubescents, and Adults

Previous studies have shown that homosexual men erotically attracted to physically mature partners (androphiles) reach puberty earlier, on average, than comparable heterosexual men. This study investigated whether the same early onset of puberty is observed in homosexual men attracted to children (pedophiles) or to pubescents (hebephiles). Subjects were 721 white, male, convicted sexual offenders, originally part of a large-scale study of sexual offending. Homosexual offenders against adults reached puberty earlier than heterosexual offenders against adults, and homosexual offenders against pubescents reached puberty earlier than heterosexual offenders against pubescents. In contrast, there was no difference between the homosexual and the heterosexual offenders against children on this variable. These results suggest that homosexual hebephilia has more etiological factors in common with androphilia than does homosexual pedophilia.     

Visual Reaction Time and Plethysmography as Measures of Sexual Interest in Child Molesters

It is important to determine the sexual interests of those accused of child molestation. Visual reaction time and plethysmography are two means of measuring sexual interest with some objectivity, but there has been no direct comparison of these methodologies. The reliability and validity of visual reaction time and plethysmography were evaluated in groups of individuals with sexual interest in children of various ages and genders. Results showed that both methods of assessment had a high reliability and validity. Visual reaction time has the added advantages that it can be used without nude slides and is a briefer assessment.     

Abnormal amygdala activation profile in pedophilia

Despite considerable public interest research in neurobiological correlates of pedophilia is scarce. Since amygdala activation is central for emotional valuation, arousal, and salience, we investigated the activation profile of this structure in 10 male subjects with pedophilia (exclusively attracted to boys), all convicted sex-offenders and sentenced to forensic psychiatric treatment along with ten male heterosexual matched controls. We used a sexually non-explicit functional Magnetic Resonance Imaging (fMRI) paradigm with images of men, women, boys or girls randomly embedded in neutral target/non-target geometrical symbols. We applied statistical parametric mapping (SPM2) and SPSS 14 for image processing and analysis. While controls activated significantly less to pictures of children compared to adults, the activation profile was reversed in subjects with pedophilia, who exhibited significantly more activation to children than adults. The highest activation was observed for boys in the patient group, and for women in control participants. Our data show enhanced activation to children's pictures even in an incidental context and suggest the provocative hypothesis that a normally present mechanism for reduced emotional arousal for children relative to adults is reversed in pedophilia, suggesting a neural substrate associated with deviant sexual preference in this condition. More extensive research in this field would be of benefit for both the victims and the offenders.