New research into psychopathy has provided evidence for the physiological nature of this mental disorder that takes it further from the realm of psychology into the realm of physiology and medicine.

The evidence for the physiological nature of this mental disorder comes from a study at the University of Wisconsin-Madison. Researchers compared the brain structure and function of normal participants to those of participants diagnosed as psychopaths. The researchers discovered that psychopaths not only have less co-activation between their amygdala, the area of the brain associated with fear and anxiety, and the ventromedial prefrontal cortex, the area of the brain usually associated with empathy and guilt, but psychopaths have less connective tissue (white matter) between the two regions [Science Daily - Brain Form and Function].

This research provides clear evidence for the physiological nature of psychopathy, and future research could pinpoint other brain structures and functions that are damaged in psychopaths.

Of course, a better physiological understanding of this mental disorder might take away some of the stigma associated with the psychological disorder, since more people will come to see the disorder as a medical problem. More importantly, the physiological nature of psychopathy could lead to improved diagnosis techniques.

In the United States, most physicians, psychiatrists and psychologists use the “Diagnostic and Statistical Manual of Mental Disorders IV” (DSM-IV) to diagnosis patients with psychopathy. Unfortunately, the DSM-IV is heavily criticized for being subjective and focusing on superficial symptoms. Moreover, the time span required for some diagnoses and the need for self-reported data can lead to misdiagnosis or under-diagnosis. For example, Dr. Robert Hare, creator of the Psychopathy Checklist and writer of “Snakes in Suits: When Psychopaths Go to Work” claims that many psychopaths will go undiagnosed.

Given that recent studies used fMRI scans to test for Alzheimer’s disease [Science Daily - Noninvasive Brain Stimulation], it is now likely that a modified fMRI could diagnosis patients as psychopaths by determining the amount of white matter between the ventromedial prefrontal cortex and amygdala. This fMRI diagnostic test would require further research with a lot more participants to determine the exact difference between the white matter of psychopaths and normal individuals, but it seems that a possible diagnostic test could be developed in the near future.

A diagnostic fMRI test would have several advantages over the traditional diagnostic methods. The fMRI would not rely on self-reported data, which is very useful since most psychopaths lie habitually. Also, the fMRI test would not be as subjective as the tests designed by the DSM-IV. Moreover, the typical time required to diagnosis someone as a psychopath is extensive. The process typically includes several interviews and administered tests; a diagnostic fMRI test would most likely be performed in under an hour.

Once diagnosed, can this research lead to better treatments for the mental disorder?

Sadly, the research by the University of Wisconsin-Madison is not currently aimed at treating this mental disorder. Psychopathy is typically treated as a personality disorder, so most research is aimed at treating it as a psychological condition. The study performed by researchers at the University of Wisconsin-Madison is important because it finally provides clear comparative evidence that the mental disorder has physiological symptoms (and probably causes) that should be treated as other medical conditions. So, possible treatments for psychopaths are limited and are much further in the future than the possibility of a diagnostic test.

Yet, the research does point to two possible treatments: brain stimulation and chemical medication.

Last year, researchers discovered they could help stroke patients regain motor control by stimulating parts of the brain associated with movement with transcranial direct current stimulation (tDCS). The patients’ brain even showed a greater amount of activation after stimulated by tDCS [Psychiatrist.com - Transcranial Magnetic Stimulation]. This is coupled with research that suggests transcranial magnetic stimulation (TMS) can be used to relieve symptoms in another psychological disorder with physiological symptoms - schizophrenia [Wikipedia - Oxytocin].

It is very possible that in the near future, researchers will try to strengthen the amygdala and ventromedial prefrontal cortex in psychopaths, along with the white matter between the two brain regions, via similar electrical or magnetic stimulation. This research could be performed rather cheaply and humanely, since there are little known side effects to the two treatments. While it is impossible to determine the outcome of such a study, if the underlying problem of psychopaths has not caused permanent damage to these regions of the brain, it seems likely that brain stimulation might be a possible treatment option.

Another potential treatment is the use of chemicals to stimulate affected brain regions. It has long been noted in neuroscience that certain brain functions and brain regions use certain neurotransmitters. For example, oxytocin is often considered the cuddly neurotransmitter because it is associated with sexual reproduction and social bonding [MIT News - Mutations and Psychiatric Illness]. Yet, this research is much further down the road. Researchers will need to determine if psychopaths are lacking any neurotransmitters, or if their affected systems rely on certain neurotransmitters.

So, treatments for psychopaths are not as promising as the ability to diagnose psychopaths, but continued research into the physiological side of mental disorders should continue provide evidence for medical intervention and the physiological cause of psychopathy. Until then, it is nice to see that psychopathy is following both bipolar disorder and schizophrenia in becoming considered a physiological disorder instead of a purely psychological one [Science Daily - Psychopath Brain Differences].