Amygdaloid volume loss in psychopathy

Tiihonen, J.; Hodgins, S.; Vaurio, O.; Laakso, M.; Repo, E.; Soininen, H.; Aronen, H. J.; Nieminen, P.; Savolainen, L.

Psychopaths commit more nonviolent and violent crimes than any other type of offender. They display deficits in fear conditioning and activation of somatic markers in anticipation of punishment. It was hypothesized that these characteristics might be related to amygdaloid abnormalities. Magnetic resonance imaging was used to examine amygdaloid volumes in 28 violent offenders and 34 healthy men with no criminal record. Of the offenders, 13 obtained high scores (HDP), and 15 moderate or low scores (MLDP) on the personality traits arrogant, deceitful interpersonal conduct and deficient affective experience assessed using Hare's Psychopathy Checklist - Revised (PCL-R). The HDP offenders had 20% to 21% smaller amygdaloid volumes on the right compared with both the MLDP offenders and the non-offenders. This difference was statistically significant after adjusting for the effects of age, intelligence and duration of alcohol abuse. There were significant negative correlations between the right amygdaloid volumes and the PCL-R ratings of the psychopathic personality traits. The results indicate that in male offenders, psychopathic personality traits are associated with amygdaloid volume loss.