Lithium appears to increase gray matter in the brains of patients who use
the drug, according to a report that will appear in Biological
Psychiatry in July.
In a statement about the study released prior to publication,
neuroscientists at UCLA said they have shown that lithium, long the standard
treatment for bipolar disorder, increases the amount of gray matter in the
brains of patients with the illness.
"Bipolar patients who were taking lithium had a striking increase in
gray matter in the cingulate and paralimbic regions of the brain,"
Carrie Bearden, Ph.D., a clinical neuropsychologist and assistant professor of
psychiatry at UCLA said in the statement. "These regions regulate
attention, motivation, and emotion, which are profoundly affected in bipolar
In this study, Bearden and colleagues at UCLA used computer analysis to
analyze brain scans collected by collaborators at the University of Pittsburgh
in order to determine whether bipolar patients showed changes in brain tissue
and, if so, whether those changes were influenced by lithium treatment.
They employed high-resolution MRI and cortical pattern-matching methods to
map gray-matter differences in 28 adults with bipolar disorder — 70
percent of whom were treated with lithium—and 28 healthy control
subjects. Detailed spatial analyses of gray-matter distribution were conducted
by measuring local volumes of gray matter at thousands of locations in the
While the brains of lithium-treated bipolar patients did not differ from
those of the control subjects in total white-matter volume, their overall
gray-matter volume was significantly higher, sometimes by as much as 15
Although other studies have measured increases in the overall volume of the
brain, Bearden said, this imaging method allowed the researchers to see
exactly which brain regions were affected by lithium. These new findings
suggest that lithium may work by increasing the amount of gray matter in
particular brain areas, which in turn suggests that existing gray matter in
these regions of bipolar brains may be underused or dysfunctional.
Bearden added that there is no evidence that the increase in gray matter
persists if lithium treatment is discontinued. "But it does suggest that
lithium can have dramatic effects on gray matter in the brain," she
said. "This may be an important clue as to how and why it works."▪