Subcortical gray matter volume abnormalities in healthy bipolar offspring: potential neuroanatomical risk marker for bipolar disorder?
OBJECTIVE
A growing number of structural neuroimaging studies have shown that bipolar disorder (BD) is associated with gray matter (GM) volume abnormalities in brain regions known to support affect regulation. The goal of this study was to examine whole-brain regional GM volume in healthy bipolar offspring (HBO) relative to age-matched controls to identify possible structural abnormalities that may be associated with risk for BD.


METHODS
Participants were 20 youths (8-17 years old) with at least one parent diagnosed with BD, and 22 age-matched healthy individuals. All of them were free of Axis I diagnoses. High-resolution magnetic resonance imaging structural images were acquired using a 3-T Siemens scanner. Voxel-based morphometric analyses were conducted using SPM5.


RESULTS
Relative to controls, HBO had significantly increased GM volume in left parahippocampal/hippocampal gyrus (p <.05 corrected), following whole-brain analyses. This increase was correlated with puberty but not age in HBO. Region-of-interest analyses on the amygdala and orbitomedial prefrontal cortex did not yield any significant group differences after conducting small volume correction.


CONCLUSIONS
The pattern of increased GM volume in parahippocampal/hippocampal gyrus in HBO suggests a potential marker for risk for BD. It can also be considered as a potential neuroprotective marker for the disorder because HBO were free of current psychopathology. Prospective studies examining the relationship between changes in GM volume in these regions and subsequent development of BD in HBO will allow us to elucidate further the role of this region in either conferring risk for or protecting against the development of BD.
Ladouceur
Cecile D
CD
All of the authors are with the Department of Psychiatry, University of Pittsburgh School of Medicine.. Electronic address: ladouceurcd@upmc.edu.
Almeida
Jorge R C
JRC
All of the authors are with the Department of Psychiatry, University of Pittsburgh School of Medicine.
Birmaher
Boris
B
All of the authors are with the Department of Psychiatry, University of Pittsburgh School of Medicine.
Axelson
David A
DA
All of the authors are with the Department of Psychiatry, University of Pittsburgh School of Medicine.
Nau
Sharon
S
All of the authors are with the Department of Psychiatry, University of Pittsburgh School of Medicine.
Kalas
Catherine
C
All of the authors are with the Department of Psychiatry, University of Pittsburgh School of Medicine.
Monk
Kelly
K
All of the authors are with the Department of Psychiatry, University of Pittsburgh School of Medicine.
Kupfer
David J
DJ
All of the authors are with the Department of Psychiatry, University of Pittsburgh School of Medicine.
Phillips
Mary L
ML
All of the authors are with the Department of Psychiatry, University of Pittsburgh School of Medicine.
D000293:Adolescent; D000367:Age Factors; D000679:Amygdala / Q000473:pathology; D001714:Bipolar Disorder / Q000175:diagnosis / Q000235:genetics* / Q000503:physiopathology; D001921:Brain / Q000473:pathology*; D002648:Child; D004292:Dominance, Cerebral / Q000502:physiology; D004644:Emotions / Q000502:physiology; D005260:Female; D020022:Genetic Predisposition to Disease / Q000235:genetics; D006624:Hippocampus / Q000473:pathology; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D020534:Parahippocampal Gyrus / Q000473:pathology; D017397:Prefrontal Cortex / Q000473:pathology; D011627:Puberty; D012016:Reference Values