Psychopathy

Study: Psychopaths Have "Potholed" Brains

Kate Kelland
Reuters/ABC Science
Mon, 10 Aug 2009 00:00 CEST

The study may open the way to the development of treatments for dangerous psychopaths in the future

Psychopaths have faulty connections between the part of the brain dealing with emotions and that which handles impulses and decision-making, scientists have found. 

In a study of psychopaths who had committed murder, manslaughter, multiple rape, strangulation and false imprisonment, the British scientists found that roads linking the two crucial brain areas had "potholes", while those of non-psychopaths were in good shape. 

The study opens up the possibility of developing treatments for dangerous psychopaths in the future, says Dr Michael Craig of the Institute of Psychiatry at London's King's College Hospital, and may have profound implications for doctors, researchers and the criminal justice system. 

"These were particular serious offenders with psychopathy and without any other mental illnesses," he says. 

"Essentially what we found is that the connections in the psychopaths were not as good as the connections in the non-psychopaths. 

"I would describe them as roads between the two areas, and we found that in the psychopaths, the roads had potholes and weren't very well maintained." 

Timing is Key 

The scientists caution against suggestions the study could lead to screening of potential psychopathic criminals before they are able to commit crimes, saying their findings had not established how, when or why the brain links were damaged. 

Psychopathic extremes have been portrayed in Hollywood blockbusters by characters like the serial killer and cannibal Hannibal Lecter. 

They often violate social norms, are manipulative, impulsive and sensation-seeking, and appear to feel no empathy or remorse. 

Craig, who is lead author of the study, published in the journal Molecular Psychiatry, stresses that the number of brain scans in the study was small, with only nine psychopaths analysed compared to nine non-psychopaths. 

"Trying to get people of this particular type to take part in a study, and also then deal with all the security you need to get them into a brain scanner, is not an easy feat," he says. 

The study used a new brain imaging technology to further analyse psychopaths' brains after previous studies found that the amygdala part of the brain, which processes emotions, and orbitofrontal cortex, which handles impulses and decisions, are structurally and functionally different in psychopaths. 

"Up until recently the technology hasn't been available to look at the connections between those two brain areas in any meaningful way," says Craig. 

But a new technique, called diffusion tensor magnetic resonance imaging (DT-MRI), allows the researchers to look at the white matter tract linking the two key brain areas. 

As well as finding clear structural deficits in the tract in psychopathic brains, they also found the degree of abnormality was significantly linked to the degree of psychopathy. 

"As for the moral significance for society, and how society wants to deal with these things, that is a little premature," says Craig. 

"This is a small study and the important thing it raises is that more research needs to be done."