Relationship of lithium concentrations in the brain measured by lithium-7 magnetic resonance spectroscopy to treatment response in mania.

Lithium concentrations in the brain were measured in 14 manic patients with bipolar disorder (12 with bipolar disorder, manic, and 2 with bipolar disorder, not otherwise specified, by DSM-III-R) by the use of lithium-7 magnetic resonance spectroscopy ([7Li]MRS). The reduction of Petterson Mania Rating Scale 4 weeks after the initiation of lithium treatment was not significantly correlated with concentrations in serum (r = 0.33), but was correlated with concentrations in the brain (r = 0.64; p < 0.05). These results suggest that the treatment response to lithium in manic patients with bipolar disorder is more closely related to the lithium concentration in the brain as measured by [7Li]MRS than to the concentration in serum.