To assess the safety and feasibility of prescribing long term lithium to elderly people with mild to moderate Alzheimer's disease (AD).

An open label treatment group with low dose lithium for up to 1 year with the Lithium Side Effects Rating Scale as the primary outcome measure. A comparison group matched for cognition and age not receiving lithium therapy.

Twenty‐two people with AD initiated lithium. Fourteen participants discontinued therapy after a mean of 16 weeks of treatment compared to the 39 weeks for those continuing to take treatment at the end of the study. Three patients discontinued treatment due to possible side effects that abated on ceasing therapy. The reports of side effects on the primary outcome scale did not differ between those discontinuing therapy and those remaining in the study. Two patients died whilst receiving lithium––in neither case was the treatment felt to be related to cause of death. There was no difference in deaths, drop outs or change in MMSE between those receiving lithium and the comparison group.

Lithium treatment in elderly people with AD has relatively few side effects and those that were apparently due to treatment were mild and reversible. Nonetheless discontinuation rates are high. The use of lithium as a potential disease modification therapy in AD should be explored further but is not without problems. Copyright © 2008 John Wiley & Sons, Ltd.