Sexually dimorphic features of vermis morphology in bipolar disorder.
OBJECTIVE
The cerebellar vermis is increasingly implicated in bipolar disorder (BD). In this study, we investigated vermis morphology in BD using a quantitative volumetric analysis.


METHODS
Volumes for total vermis and vermis subregions V1 (lobules I-V), V2 (lobules VI-VII), and V3 (lobules VIII-X) were calculated using high-resolution structural magnetic resonance imaging obtained from 44 individuals with BD (25 females and 19 males) and 43 healthy comparison (HC) subjects (26 females and 17 males). Total vermis volumes were compared between the BD and HC groups. Potential effects of vermis subregions and clinical features were explored.


RESULTS
Total vermis volumes were significantly larger in the BD group than in the HC group (p = 0.02). There was a significant group-by-sex interaction (p = 0.02). Total vermis volumes were significantly larger in males with BD than HC males (p = 0.004); vermis volumes did not differ significantly between females with and without BD (p = 0.95). Subregion analyses showed a trend-level interaction between diagnosis and subregion (p = 0.07) in which subregion V1 volumes were significantly larger in BD participants (p = 0.001), with differences primarily driven by males (p = 0.001).


CONCLUSIONS
Our findings demonstrate increases in cerebellar vermis volumes in males with BD. These findings support the presence of structural alterations in the cerebellar vermis in BD and furthermore the influence of sex on such changes.
Department of Psychiatry, Yale University School of Medicine, New Haven, CT 06511, USA. fay.womer@yale.edu
Fay Y
FY
Womer
Fei
F
Wang
Lara G
LG
Chepenik
Jessica H
JH
Kalmar
Linda
L
Spencer
Erin
E
Edmiston
Brian P
BP
Pittman
R Todd
RT
Constable
Xenophon
X
Papademetris
Hilary P
HP
Blumberg
D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D001714:Bipolar Disorder / Q000473:pathology*; D002531:Cerebellum / Q000473:pathology*; D039721:Diagnostic and Statistical Manual of Mental Disorders; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D012737:Sex Factors; D055815:Young Adult