Prophylactic therapy with lithium in elderly patients with unipolar major depression

To compare the relapse rate of elderly depressed patients taking low dose lithium as an additional therapy with antidepressant medication to those receiving antidepressant medication alone.

Fifty elderly subjects recovering from a major depressive illness taking continuation antidepressants were randomised, in a double blind study, to receive additional lithium carbonate or placebo and followed up over a two year period for evidence of relapse.

Relapse rate was significantly greater in those subjects taking antidepressant medication alone compared to subjects taking additional lithium therapy. After six months four (17%) subjects taking antidepressant medication alone had relapsed, whereas none of the subjects taking additional lithium had relapsed. After two years eight (33%) subjects taking antidepressant medication alone had relapsed, whereas only one (4%) of the subjects taking additional lithium had relapsed.

This preliminary study suggests that long-term low dose lithium therapy is well tolerated and protects elderly patients from a relapse of depressive illness.