Brain pathology in pedophilic offenders: evidence of volume reduction in the right amygdala and related diencephalic structures.
BACKGROUND
Pedophilic crime causes considerable public concern, but no causative factor of pedophilia has yet been pinpointed. In the past, etiological theories postulated a major impact of the environment, but recent studies increasingly emphasize the role of neurobiological factors, as well. However, the role of alterations in brain structures that are crucial in the development of sexual behavior has not yet been systematically studied in pedophilic subjects.


OBJECTIVE
To examine whether pedophilic perpetrators show structural neuronal deficits in brain regions that are critical for sexual behavior and how these deficits relate to criminological characteristics.


METHODS
Amygdalar volume and gray matter of related structures that are critical for sexual development were compared in 15 nonviolent male pedophilic perpetrators (forensic inpatients) and 15 controls using complementary morphometric analyses (voxel-based morphometry and volumetry). Psychosocial adjustment and sexual offenses were also assessed.


RESULTS
Pedophilic perpetrators showed a significant decrease of right amygdalar volume, compared with healthy controls (P = .001). We observed reduced gray matter in the right amygdala, hypothalamus (bilaterally), septal regions, substantia innominata, and bed nucleus of the striae terminalis. In 8 of the 15 perpetrators, enlargement of the anterior temporal horn of the right lateral ventricle that adjoins the amygdala could be recognized by routine qualitative clinical assessment. Smaller right amygdalar volumes were correlated with the propensity to commit uniform pedophilic sexual offenses exclusively (P = .006) but not with age (P = .89).


CONCLUSIONS
Pedophilic perpetrators show structural impairments of brain regions critical for sexual development. These impairments are not related to age, and their extent predicts how focused the scope of sexual offenses is on uniform pedophilic activity. Subtle defects of the right amygdala and closely related structures might be implicated in the pathogenesis of pedophilia and might possibly reflect developmental disturbances or environmental insults at critical periods.
Schiltz
Kolja
K
Department of Psychiatry, Otto von Guericke University, Magdeburg, Saxony-Anhalt 39120, Germany. kolja.schiltz@med.ovgu.de
Witzel
Joachim
J
Northoff
Georg
G
Zierhut
Kathrin
K
Gubka
Udo
U
Fellmann
Hermann
H
Kaufmann
Jörn
J
Tempelmann
Claus
C
Wiebking
Christine
C
Bogerts
Bernhard
B
D000328:Adult; D000679:Amygdala / Q000473:pathology*; D001284:Atrophy; D001921:Brain / Q000473:pathology*; D002552:Cerebral Ventricles / Q000473:pathology; D004027:Diencephalon / Q000473:pathology*; D005555:Forensic Psychiatry; D007839:Functional Laterality; D006760:Hospitalization; D006801:Humans; D007031:Hypothalamus / Q000473:pathology; D007091:Image Processing, Computer-Assisted; D008297:Male; D008875:Middle Aged; D010378:Pedophilia / Q000175:diagnosis / Q000473:pathology* / Q000523:psychology; D011606:Psychosexual Development / Q000502:physiology; D012742:Sex Offenses / Q000706:statistics & numerical data*; D012725:Sexual Behavior / Q000523:psychology; D012917:Social Adjustment