Diagnostic and sex effects on limbic volumes in early-onset bipolar disorder and schizophrenia.
OBJECTIVE
The limbic structures in early-onset schizophrenia-spectrum illness (SZ) and bipolar disorder (BPD) were studied to discern patterns associated with diagnosis and sex.


METHODS
Thirty-five youths with DSM-IV BPD without psychosis, 19 with BPD with psychosis, 20 with SZ, and 29 healthy controls (HC), similar in age (6-17 years) and sex, underwent structured and clinical interviews, neurological examination, and cognitive testing. Structural magnetic resonance images (MRIs) were acquired on a 1.5 Tesla, General Electric Signa Scanner. Differences in subcortical brain volumes, including the amygdala and hippocampus, were evaluated using two-way (diagnosis, sex) univariate analyses covarying for total cerebral volume and age.


RESULTS
Youth with SZ and BPD showed no differences in amygdala and hippocampal volumes. However, boys with SZ had smallest left amygdala and girls with BPD had the smallest left hippocampal volumes. In exploratory analyses, SZ showed reduced thalamic volumes bilaterally and both BPD groups had larger right nucleus accumbens (NA) volumes relative to HC.


CONCLUSIONS
There were no limbic volumetric differences between BPD and SZ. However, there were diagnosis-by-sex interactions in the amygdala and hippocampus, structures that are rich in sex hormone receptors. In addition, smaller thalamus was associated with SZ while larger right NA volumes were most related to BPD. This study underscores the importance of assessing diagnostic effects and sex effects on the brain in future studies and provides evidence that boys and girls with SZ and BPD may have differential patterns of neuropathology associated with disease expression.
Frazier
Jean A
JA
Department of Psychiatry, Harvard Medical School, Massachusetts, USA. JFrazier@challiance.org
Hodge
Steven M
SM
Breeze
Janis L
JL
Giuliano
Anthony J
AJ
Terry
Janine E
JE
Moore
Constance M
CM
Kennedy
David N
DN
Lopez-Larson
Melissa P
MP
Caviness
Verne S
VS
Seidman
Larry J
LJ
Zablotsky
Benjamin
B
Makris
Nikos
N
D000293:Adolescent; D017668:Age of Onset; D000679:Amygdala / Q000033:anatomy & histology / Q000503:physiopathology; D001714:Bipolar Disorder / Q000175:diagnosis* / Q000453:epidemiology / Q000503:physiopathology*; D002648:Child; D005260:Female; D006624:Hippocampus / Q000033:anatomy & histology / Q000503:physiopathology; D006801:Humans; D008032:Limbic System / Q000033:anatomy & histology*; D008279:Magnetic Resonance Imaging; D008297:Male; D012561:Schizophrenia, Childhood / Q000175:diagnosis* / Q000453:epidemiology / Q000503:physiopathology*; D012720:Severity of Illness Index; D012737:Sex Factors