Reversal
of brain volumetric abnormality in bipolar
patients by lithium
Recent
neuroimaging studies have demonstrated selective
structural changes in the brains of depressed
patients. In particular morphological and
functional abnormalities have been reported in
the cingulate cortex, which plays a key role in
mood disorders. The possible involvement of
anatomic abnormalities of the cingulate in
bipolar disorder has been investigated in 11
untreated bipolar patients and 16 bipolar
patients treated with lithium as monotherapy wer
compared with 39 healthy control subjects. Using
magnetic resonance imaging (MRI) the volumes of
gray matter at the right and left anterior and
posterior cingulate cortices were measured
blindly, with coronal slices of 1.5 mm.
MRI images revealed a decrease of left anterior
cingulate volumes in teh untreated bipolar
patients in comparison with controls ( 2.4
cm3 and 2.9 cm3,
respectively). However, the volumes of the left
anterior cingulate in lithium-treated bipolar
patients were not significantly different from
those of control subjects ( 3.3
cm3).
This study thus confirms the existence of
anatomical abnormalities in the left anterior
cingulate cortex in bipolar patients. Lithium
monotherapy appears capable of preventing
atrophy of this important brain area or
reversing the cingulate volume back to normal
levels. Replication of these results in a larger
and longitudinal study would help better
understand the involvement of cingulate
abnormalities in the pathophysiology of bipolar
disorder and mood disorders in general. Sassi
RB, Brambilla P, Hatch JP, Nicoletti MA,
Mallinger AG, Frank E, Kupfer DJ, Keshavan MS,
Soares JC. Reduced left anterior cingulate
volumes in untreated bipolar patients. Biol
Psychiatry 56: 467-475, 2004.