Background: Although studies of neurologic patients have suggested that prefrontal structural impairments may predispose to sociopathy, it is unknown whether there is a relationship between psychopathy and prefrontal volume in individuals from the community and whether any prefrontal structural impairment is specific to "unsuccessful" (caught) psychopaths as opposed to "successful" (uncaught) psychopaths. This study tests the hypothesis that psychopathy is associated with a reduction in prefrontal gray volume but that this abnormality is specific to unsuccessful psychopaths.
Method: Prefrontal gray and white matter volumes were assessed using structural magnetic resonance imaging (MRI) in 16 unsuccessful psychopaths, 13 successful psychopaths, and 23 control subjects.
Results: Higher total as well as subfactor psychopathy scores (arrogant/deceptive, affective, and impulsive/unstable) were all associated with low prefrontal gray volume. Unsuccessful psychopaths, but not successful psychopaths, had a 22.3% reduction in prefrontal gray matter volume compared with control subjects.
Conclusions: These results demonstrating for the first time a prefrontal structural deficit in community psychopaths provide partial support for a prefrontal theory of psychopathy but highlight an important difference between successful and unsuccessful psychopaths.