Negative interaction between lithium and electroconvulsive therapy--a case-control study.

Background: Concurrent use of lithium and ECT is suspected to increase neurotoxicity.

Method: A retrospective case-control study over an eight-year period was conducted to investigate the adverse effects of a combined lithium/ECT treatment. Thirty-one subjects with combined lithium/ECT treatment were compared with a control group (ECT only) of 135 cases matched for age and sex.

Results: Most cases in both groups had no adverse effects. Three (10%) study group subjects and 15 (11%) controls experienced brief delirium. Three controls and none of the subjects developed a prolonged confusion. There were no significant differences in the profile of other adverse effects between the two groups.

Conclusion: Prescription of lithium together with ECT was not associated with higher frequency of adverse effects.