Neurobiological roots of psychopathy.

Psychopathy is an extreme form of antisocial behavior, with about 1% prevalence in the general population, and 10-30% among incarcerated criminal offenders. Although the heritability of severe antisocial behavior is up to 50%, the genetic background is unclear. The underlying molecular mechanisms have remained unknown but several previous studies suggest that abnormal glucose metabolism and opioidergic neurotransmission contribute to violent offending and psychopathy. Here we show using iPSC-derived cortical neurons and astrocytes from six incarcerated extremely antisocial and violent offenders, three nonpsychopathic individuals with substance abuse, and six healthy controls that there are robust alterations in the expression of several genes and immune response-related molecular pathways which were specific for psychopathy. In neurons, psychopathy was associated with marked upregulation of RPL10P9 and ZNF132, and downregulation of CDH5 and OPRD1. In astrocytes, RPL10P9 and MT-RNR2 were upregulated. Expression of aforementioned genes explained 30-92% of the variance of psychopathic symptoms. The gene expression findings were confirmed with qPCR. These genes may be relevant to the lack of empathy and emotional callousness seen in psychopathy, since several studies have linked these genes to autism and social interaction.

Correction: Neurobiological roots of psychopathy.

A correction to this paper has been published and can be accessed via a link at the top of the paper.

Psychopathic traits in a representative sample of Finnish male prisoners.

BACKGROUND: The psychopathic traits measured with the Hare Psychopathy Checklist-Revised (PCL-R) in a representative national prisoner sample have not been studied in Finland before. It has been unclear whether there could occur some national differences or whether the PCL-R can be used for assessing psychopathic traits in the Finnish forensic settings. AIMS: Our aim was to study the distribution of psychopathic traits in the Finnish male prisoners as well as the correlations of these traits with DSM-IV disorders and to compare the sample with similar samples of Europe and America. METHODS: 171 male prisoners representing all Finnish sentenced male offenders (about 3300) were studied using the PCL-R, SCID-I and SCID-II. RESULTS: The results of the first Finnish study utilizing the PCL-R in a representative national sample of male prisoners were quite similar to the findings of the previous studies of male prisoners carried out in North America, the UK and Sweden. The scores of the interpersonal facet are lower in this sample than in the sample of North America. In total, 16.4% of the Finnish male prisoners can be diagnosed as having a psychopathic disorder. CONCLUSIONS: The PCL-R is a reliable and valid measure of the psychopathy construct of the Finnish male prisoners. The PCL-R is applicable to the Finnish offenders and it is a useful tool for assessing psychopathy in the Finnish criminal justice settings.