Abnormal interhemispheric connectivity in male psychopathic offenders.

BACKGROUND: Psychopathic offenders inevitably violate interpersonal norms and frequently resort to aggressive and criminal behaviour. The affective and cognitive deficits underlying these behaviours have been linked to abnormalities in functional interhemispheric connectivity. However, direct neurophysiological evidence for dysfunctional connectivity in psychopathic offenders is lacking. METHODS: We used transcranial magnetic stimulation combined with electroencephalography to examine interhemispheric connectivity in the dorsolateral and motor cortex in a sample of psychopathic offenders and healthy controls. We also measured intracortical inhibition and facilitation over the left and right motor cortex to investigate the effects of local cortical processes on interhemispheric connectivity. RESULTS: We enrolled 17 psychopathic offenders and 14 controls in our study. Global abnormalities in right to left functional connectivity were observed in psychopathic offenders compared with controls. Furthermore, in contrast to controls, psychopathic offenders showed increased intracortical inhibition in the right, but not the left, hemisphere. LIMITATIONS: The relatively small sample size limited the sensitivity to show that the abnormalities in interhemispheric connectivity were specifically related to the dorsolateral prefrontal cortex in psychopathic offenders. CONCLUSION: To our knowledge, this study provides the first neurophysiological evidence for abnormal interhemispheric connectivity in psychopathic offenders and may further our understanding of the disruptive antisocial behaviour of these offenders.

White matter deficits in psychopathic offenders and correlation with factor structure.

Psychopathic offenders show a persistent pattern of emotional unresponsivity to the often horrendous crimes they perpetrate. Recent studies have related psychopathy to alterations in white matter. Therefore, diffusion tensor imaging followed by tract-based spatial statistics (TBSS) analysis in 11 psychopathic offenders matched to 11 healthy controls was completed. Fractional anisotropy was calculated within each voxel and comparisons were made between groups using a permutation test. Any clusters of white matter voxels different between groups were submitted to probabilistic tractography. Significant differences in fractional anisotropy were found between psychopathic offenders and healthy controls in three main white matter clusters. These three clusters represented two major networks: an amygdalo-prefrontal network, and a striato-thalamo-frontal network. The interpersonal/affective component of the PCL-R correlated with white matter deficits in the orbitofrontal cortex and frontal pole whereas the antisocial component correlated with deficits in the striato-thalamo-frontal network. In addition to replicating earlier work concerning disruption of an amygdala-prefrontal network, we show for the first time that white matter integrity in a striato-thalamo-frontal network is disrupted in psychopathic offenders. The novelty of our findings lies in the two dissociable white matter networks that map directly onto the two major factors of psychopathy.

Inhibitory deficits in the dorsolateral prefrontal cortex in psychopathic offenders.

Often typified as cunning social predators, psychopathic offenders show a persistent pattern of impulsive and reckless behavior, the pathophysiology of which has been related to dysfunction in the dorsolateral prefrontal cortex (DLPFC). That is, the DLPFC is important for the regulatory control of impulses and emotion as well as working memory and psychopathic offenders show impairments in all three dimensions. In the present study, we used combined transcranial magnetic stimulation and electroencephalography to compare the physiology of the DLPFC in 13 psychopathic offenders and 15 healthy subjects vis à vis excitability and inhibition. In addition, working memory performance was measured through the letter-number sequencing test. Results showed that compared to healthy subjects, psychopathic offenders had inhibition not excitability deficits in the DLPFC that was accompanied by deficits in working memory performance. In healthy controls and psychopathic offenders working memory performance correlated with the extent of inhibition over the DLPFC. Taken together, these findings suggest that psychopathic offenders suffer from dysfunctional inhibitory neurotransmission in the DLPFC and impaired working memory which may account for the behavioral impairments associated with this disorder.

Sexual offenders' state-of-mind regarding childhood attachment: a controlled investigation.

Attachment experiences have been regarded as significant by researchers and clinicians attempting to explain the etiology of sexual offending. Although initial studies have revealed some promising evidence, there are a number of theoretical and methodological problems with this preliminary body of work. While addressing these limitations, the goal of the present study was to investigate state-of-mind regarding childhood attachment among subtypes of sexual offenders, comparing them to both a sample of nonsexual offenders and to the documented patterns of nonoffenders. Sixty-one sexual offenders (extrafamilial child molesters, incest offenders, and rapists) and 40 nonsexual offenders (violent and nonviolent) were administered the "Adult Attachment Interview." Results indicated that the majority of sexual offenders were insecure, representing a marked difference from normative samples. Although insecurity of attachment was common to all groups of offenders, there were important differences in regard to the specific type of insecurity. Most notable were the child molesters, who were significantly more likely to be Preoccupied. Rapists, violent offenders, and, to a lesser degree, incest offenders were more likely to be Dismissing. Although still most likely to be Dismissing, nonviolent offenders were comparatively more Secure.

An exploration of childhood victimization and family-of-origin characteristics of sexual offenders against children.

A comparison of the childhood victimization experiences and family-of-origin characteristics of 33 sexual offenders against children, 66 violent offenders, and 25 nonviolent offenders participating in assessment or treatment at a forensic division of a Canadian psychiatric hospital was undertaken using a semistructured interview designed specifically for this study. Overall, 31.5% of the sample reported contact sexual abuse (i.e., oral, vaginal, or anal) by age 14. Sexual offenders against children reported significantly more sexual abuse than both violent and nonviolent offenders and were more likely to have been sexually propositioned and exposed to. Sexual offenders against children were also more likely to report physical discipline as the primary type of discipline in the home. Analyses of the variables concerning characteristics of parents, siblings, and significant others also indicated significant differences between groups. Implications of these findings on the intergenerational hypothesis are discussed as well as their relevance for treatment.

Efficacy of a 2-year-old sexual assault nurse examiner program in a Canadian hospital.

INTRODUCTION: The purpose of this study was to describe a sexual assault nurse examiner (SANE) program at a hospital-based sexual assault care center in Ontario, Canada, and assess its efficacy in comparison with physician examiners. METHODS: Data obtained from the hospital records of 515 women who came to a Toronto sexual assault care center were examined. A number of variables relevant to this assessment of services were examined, including client demographics and presenting history, aspects of the sexual assault, and characteristics of the treatment. RESULTS: Average assessment times were shorter for victims seen by SANEs than for victims seen by physicians (approximately 3(1/4) hours versus 4 hours). Physicians had more interruptions (25.1%) than did SANEs (20.0%). Client characteristics and presentation were similar regardless of who provided care, with some exceptions. DISCUSSION: The results of the study support the utility of the SANE model as an efficient program for the assessment and treatment of victims of sexual assault.