Of the patients, treated adequately with cyclic antidepressants, about a third do not react favourably. One of the possibilities for further treatment of these `treatment resistant' patients is to add lithium to the cyclic antidepressant. In this article a literature research is presented involving all controlled and uncontrolled studies concerning the addition of lithium.

Five of the eight published controlled studies show a positive effect of lithium addition while three do not.

In contrast to earlier reports the efficacy of lithium addition does not seem to manifest itself on the short term i.c. 48 hours, but mostly at a longer term of three or more weeks.

The addition of lithium to a cyclic antidepressant seems to be a real alternative for MAO-inhibitors and ECT. The number of patients and studies available is still relatively small so the scientific base for this statement remains uncertain.