What is Psychopathy
The term psychopathy gets thrown around quite a bit to describe someone’s behavior that demonstrates a lack of empathy, but what really is it? When referring to the DSM-5 psychopathy is not going to be found, since it is actually classified as an extreme form of antisocial personality disorder (ASPD). The characteristics are hostility, aggression, impulsivity, callousness, manipulation, and deceitfulness. Therefore, psychopathy is commonly associated with violent offenders, which is true, but not in all cases: psychopathy is present in 1-3% of the general population and 10-30% of incarcerated offenders.
What Makes a Psychopath
Individuals diagnosed with extreme ASPD experience dysregulation in glucose metabolism, opioidergic neurotransmission, and gene specific dysregulation. Research has found a decrease in opioid receptor expression which explains the impulsive behavior as individuals act out to stimulate the receptor through rewarding effects. The abnormal glucose metabolism is under functioning leading to hypoglycemia in individuals. Long terms hypoglycemia could explain the aggressive behavior displayed by diagnosed individuals. Major genes associated with psychopathy are: RPL109, ZNF132, CDH5, and OPRD1. RPL109 and ZNF132 are upregulated and CDH5 and OPRD1 are downregulated. ZNF132 is expressed in the cerebellum, which regulates social behavior through dopamine release. Research has found that the neuronal expression of RPL109 and ZNF132 is abnormal. ORPD1 encodes for the opioid receptor, therefore the downregulation of this gene would explain the decrease of opioid receptors. All of these genes except ORPD1 have also been linked to Autism.
Nature vs Nurture
Psychopathy has been linked to father to son inheritance. Although not all diagnosed psychopaths had a psychopathic father. Studies have explored environmental factors but there has not been a statistical significance in diagnosed psychopaths and environmental influences. However, it is speculated that environmental factors could exacerbate genetic factors. Additionally, it is known that early childhood stress alters gene methylation and expression and childhood maltreatment and abuse increase reactive aggression. These factors could increase psychopathic symptoms but have not been linked to cause psychopathy. Therefore, psychopathy is viewed to be most influenced by nature and not nurture.
Treatment
There is currently no cure for psychopathy but there are treatments to make the condition manageable. The major treatments are therapy and medication. Cognitive Behavioral Therapy (CBT) works to correlate existing thought patterns to positive outcomes. The different medications being explored are mood stabilizers, antipsychotics, and naloxone. Mood stabilizers are used to reduce agitation and potentially violent acts. Antipsychotics are used to reduce violence and aggression and lessen the urge to harm others. Naloxone as a partial opioid receptor agonist may upregulate the opioid receptor rate in diagnosed psychopaths and counteract the symptom of low opioid receptors. Using treatments in combination would provide the most effective outcome.
Conclusion
The changes in gene expression account for the upregulation of RPL109 and ZNF132 and the downregulation of OPRD1 and CDH5. The dysregulation of these genes results in abnormal glucose metabolism and a decrease in opioid receptors in psychopathic individuals. Research has explored if psychopathy is brought on by genetics or environmental factors and has found that psychopathy is most likely genetic but can be exacerbated by environmental influences.
References
[1] Tiihonen, J., Koskuvi, M., Lähteenvuo, M. et al. Neurobiological roots of psychopathy. Mol Psychiatry 25, 3432–3441 (2020). https://doi.org/10.1038/s41380-019-0488-z.
[2] Therapist.com. What is a psychopath? Signs, causes, treatments. (2022). https://therapist.com/disorders/psychopathy/.
