It is estimated that up to a third of all people incarcerated for violent crimes may suffer from some degree of psychopathy, which limits their capacity for empathy and therefore heightens their propensity for antisocial behavior. While the causes of the condition are complex, a new study reveals that the tendency towards psychopathic violence is largely controlled by a group of genes associated with autism.
Writing in the journal Molecular Psychiatry, the study authors explain that while an intricate tapestry of genetics and environmental factors contribute to the development of psychopathy, the condition is thought to be around 50 percent hereditary. To investigate which genes are to blame, the researchers collected stem cells from the skin of six violent psychopathic convicts in Finland.
In the lab, these stem cells were induced to grow into two different types of brain cell, known as neurons and astrocytes. The team then examined the genetic profile of these cells, before comparing them to those from a group of non-psychopaths.
Results showed that alterations in the expression of four individual genes – called RPL10P9, ZNF132, CDH5, and OPRD1 – could be used to predict the prevalence of up to 92 percent of psychopathic symptoms in the criminal group.
Analyzing this finding, the researchers state that “it is remarkable that all the aforementioned genes except OPRD1 have been previously linked to autism, and might thus contribute to the emotional callousness and lack of empathy observed in psychopathic violent offenders.”
Like psychopaths, people with autism tend to have difficulties forming emotional bonds or interpreting social signals from other people.
The OPRD1 gene is particularly interesting because it helps to regulate the function of opioid receptors, suggesting that abnormalities within the body’s opioid system could be at least partially responsible for violent psychopathy. Delving deeper into this possibility, the researchers discovered that the psychopathic criminals all displayed excessively high levels of an opioid-binding protein called OPCML, and found that this too was a major predictor of antisocial behavior.
Based on these results, the authors go as far as to suggest that by interfering with opioid signaling, it may be possible to reduce the severity of psychopathic symptoms, and thereby decrease violent crime.
Medications such as naltrexone – which blocks opioid signaling and is often used to save the lives of those who have overdosed on heroin or prescription painkillers – may therefore also have a role to play in treating psychopathy.