Men diagnosed with psychopathy share similarities in brain structure that differ from the general population, a study has found — a discovery researchers say could help improve understanding and treatment of the condition.
The study compared brain scans from 39 men diagnosed with psychopathy with those from male volunteers without the disorder and found significant structural differences.
Psychopathy is a personality disorder typically marked by a chronic lack of empathy, manipulative behaviour, impulsivity and a tendency to take risks. In more severe cases, it can lead to aggression or violence.
The researchers wrote: “Psychopathy is one of the greatest risk factors for serious and persistent violence.
“In order to detect its neurobiological substrates, we examined 39 male psychopathic subjects and matched controls using structural magnetic resonance imaging and the Psychopathy Check-List (PCL-R).”
Researchers from the Research Center Jülich and RWTH Aachen University in Germany used structural magnetic resonance imaging (MRI) and the PCL-R, a clinical tool combining interviews, professional assessments and official records.
It produces three scores: an overall score, factor 1 (interpersonal and emotional traits), and factor 2 (impulsive and antisocial behaviour).
While factor 1 scores showed only slight brain structure differences, high factor 2 scores were linked to volume reductions in several brain regions.
These included the pons (which helps regulate involuntary functions), thalamus (involved in processing sensory information), basal ganglia (associated with movement and decision-making), and the insular cortex (linked to emotional processing and internal sensations).
These brain areas help support functions such as emotional regulation, interpreting sensory input, motivation and behavioural control — all of which shape how a person responds to their environment.
The researchers also found that the brains of psychopathic subjects were, on average, 1.45 per cent smaller than those in the control group, which may suggest underlying developmental differences.
They said: “The present results suggest that the behavioural disturbances that are captured by the PCL-R factor 2 are associated with volume deficits in regions which belong to frontal-subcortical circuits that could be involved in behavioural control.”
The results indicate that antisocial and impulsive behaviours seen in psychopathy could be influenced by shared neurological traits.
However, the researchers noted the study’s small sample size and limited subject diversity.
They suggest future research should consider additional factors that might influence brain structure, such as substance misuse or trauma, to better understand cause and effect.
