Lithium does not alter the choline/creatine ratio in the temporal lobe of human volunteers as measured by proton magnetic resonance spectroscopy.

OBJECTIVE

To study the effect of lithium administration on brain choline/creatine (Cho/Cr) ratios in healthy volunteers.

DESIGN

Double-blind, placebo-controlled, prospective study.

SETTING

The Nuclear Magnetic Resonance Research Unit at the University of Alberta.

PARTICIPANTS

Sixteen healthy volunteers, recruited through advertisements. Subjects were excluded if they had a physical illness, or a personal or family history of psychiatric illness. The study period was from Feb. 6, 1996, to Mar. 21, 1996.

INTERVENTIONS

Subjects received a baseline proton magnetic resonance spectroscopy (1H MRS) scan, and then were instructed to take either lithium (1,200 mg) or placebo at night for 7 days. On Day 8, the subjects returned for a second 1H MRS scan. Study participants were seen by a physician at the beginning and at the end of the experiment, and had access to the physician throughout the study period.

OUTCOME MEASURES

Ratios of Cho/Cr measured in the temporal lobes by 1H MRS.

RESULTS

There were no significant differences in the Cho/Cr ratios between the 2 groups on the test day (placebo 0.748 [standard deviation 0.29] versus lithium 0.811 [SD 0.25]; F = 0.147, p = 0.72), and there was no significant change from baseline in either group (0.003 above baseline for placebo; 0.056 above baseline for lithium; F = 1.21, p = 0.32).

CONCLUSIONS

Lithium administration to healthy volunteers does not alter the Cho/Cr ratio in temporal lobe as measured by 1H MRS. The result concurs with reports that differences in Cho/Cr ratios observed in patients with bipolar disorder are likely specific to the illness, and are not the result of lithium therapy. Hence, alterations in choline function are not involved in the clinical effectiveness of lithium.