Regional cerebral blood flow changes in female to male gender identity disorder.
OBJECTIVE
Despite a range of research on gender identity disorder (GID), at present there is no scientific consensus on whether the etiology of GID is mental or physical. In particular recent advances in the technology of neuroimaging research have led to an increased understanding of the biological basis of various mental disorders. GID also should be evaluated from this perspective. The aim of the present study was therefore to do the first trial to examine the regional cerebral blood flow (rCBF) in GID.


METHODS
Persons considered biologically male fulfilling the GID criteria are termed male to female (MTF) and, conversely, persons considered biological female are termed female to male (FTM). We compared 11 FTM subjects and nine age- and handedness-matched female control subjects. None of the subjects was regularly taking medication and none had any kind of physical or psychiatric comorbidity. To evaluate rCBF in GID subjects and control subjects, statistical parametric mapping analysis of (99m)Tc-ethyl-cysteinate dimer single-photon emission computed tomography was used.


RESULTS
GID subjects had a significant decrease in rCBF in the left anterior cingulate cortex (ACC) and a significant increase in the right insula compared to control subjects.


CONCLUSIONS
The ACC and insula are regions that have been noted as being related to human sexual behavior and consciousness. From these findings, useful insights into the biological basis of GID were suggested.
Department of Psychiatry, Faculty of Medicine, Fukuoka University, Fukuoka, Japan. nawatahide@gmail.com
Hideyuki
H
Nawata
Koji
K
Ogomori
Mariko
M
Tanaka
Ryoji
R
Nishimura
Hajime
H
Urashima
Rika
R
Yano
Koichi
K
Takano
Yasuo
Y
Kuwabara
D000328:Adult; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000000981:diagnostic imaging / Q000503:physiopathology*; D002560:Cerebrovascular Circulation / Q000502:physiology*; D005260:Female; D005783:Gender Identity; D006801:Humans; D007091:Image Processing, Computer-Assisted; D011877:Radionuclide Imaging; D014189:Transsexualism / Q000000981:diagnostic imaging / Q000503:physiopathology*