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/c reatine (Cho/Cr) ratios in healthy volunteers. Design: Double-blind, placeb o-controlled, prospective study. Setting: The Nuclear Magnetic Resonance Re search Unit at the University of Alberta. Participants: Sixteen healthy vol unteers, recruited through advertisements. Subjects were excluded if they h ad a physical illness, or a personal or family history of psychiatric illne ss. The study period was from Feb. 6, 1996, to Mar. 21, 1996. Interventions : Subjects received a baseline proton magnetic resonance spectroscopy (H-1 MRS) scan, and then were instructed to take either lithium (1200 mg) or pla cebo at night for 7 days. On Day 8, the subjects returned for a second H-1 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 th e study period. Outcome measures: Ratios of Cho/Cr measured in the temporal robes 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 de viation 0.29] versus lithium 0.811 [SD 0.25]; F = 0.147, p = 0.72), and the re was no significant change from baseline in either group (0.003 above bas eline for placebo; 0.056 above baseline for lithium; F = 1.21, p = 0.32). C onclusions: Lithium administration to healthy volunteers does not alter the Cho/Cr ratio in temporal lobe as measured by H-1 MRS. This result concurs with reports that differences in Cho/Cr ratios observed in patients with bi polar disorder are likely specific to the illness, and are not the result o f lithium therapy. Hence, alterations in choline function are not involved in the clinical effectiveness of lithium.