Regional cerebral glucose metabolic abnormalities in bipolar II depression.
BACKGROUND
Functional neuroimaging studies of bipolar disorder (BD) performed in conjunction with antidepressant treatment trials generally require that patients remain on mood stabilizers to reduce the risk of inducing mania; yet, it is unknown whether the metabolic abnormalities evident in unmedicated BD depressives remain detectable in patients receiving mood stabilizers. This study investigated whether cerebral metabolic abnormalities previously reported in unmedicated BD subjects are evident in depressed bipolar disorder type II (BD II) subjects receiving lithium or divalproex.


METHODS
Using [18F]-fluorodeoxyglucose-positron-emission tomography, cerebral glucose metabolism was compared between 13 depressed BD II subjects on therapeutic doses of lithium or divalproex and 18 healthy control subjects. Regional metabolism was compared between groups in predefined regions of interest.


RESULTS
Metabolism was increased in the bilateral amygdala, accumbens area, and anteroventral putamen, left orbitofrontal cortex and right pregenual anterior cingulate cortex in depressives versus control subjects. Post hoc exploratory analysis additionally revealed increased metabolism in left parahippocampal, posterior cingulate, and right anterior insular cortices in depressives versus control subjects. Correlational analyses showed multiple limbic-cortical-striatal interactions in the BD sample not evident in the control sample, permitting sensitive and specific classification of subjects by discriminant analysis.


CONCLUSIONS
These results confirm previous reports that bipolar depression is associated with abnormally increased metabolism in the amygdala, ventral striatum, orbitofrontal cortex, anterior cingulate, and anterior insula, and extend these results to bipolar disorder type II depressives on lithium or divalproex. They also implicate an extended functional anatomical network known to modulate visceromotor function in the pathophysiology of BD II depression.
Mah
Linda
L
Section on Neuroimaging in Mood and Anxiety Disorders, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland, USA. mahl@intra.nimh.nih.gov
Zarate
Carlos A
CA
Singh
Jaskaran
J
Duan
Yu-Fei
YF
Luckenbaugh
David A
DA
Manji
Husseini K
HK
Drevets
Wayne C
WC
D000679:Amygdala / Q000378:metabolism; D018692:Antimanic Agents / Q000627:therapeutic use; D001714:Bipolar Disorder / Q000150:complications / Q000188:drug therapy / Q000378:metabolism*; D001786:Blood Glucose / Q000378:metabolism*; D001921:Brain / Q000378:metabolism*; D001931:Brain Mapping; D003863:Depression / Q000150:complications / Q000378:metabolism* / Q000517:prevention & control; D005260:Female; D006801:Humans; D018020:Lithium Compounds / Q000627:therapeutic use; D008297:Male; D009714:Nucleus Accumbens / Q000378:metabolism; D049268:Positron-Emission Tomography; D017397:Prefrontal Cortex / Q000378:metabolism; D011699:Putamen / Q000378:metabolism; D012016:Reference Values; D014635:Valproic Acid / Q000627:therapeutic use
D018692:Antimanic Agents; D001786:Blood Glucose; D018020:Lithium Compounds; D014635:Valproic Acid