To the Editor: The article on lithium discontinuation during pregnancy by Adele C. Viguera, M.D., et al. (1) raised perplexing questions. They reported that 52% of pregnant patients and 58% of nonpregnant patients relapse in the first 40 weeks after discontinuation. Among pregnant subjects, 64% of episodes were of depressive or mixed type. This raises the question whether some women should receive prophylactic antidepressant therapy during pregnancy after discontinuing lithium. That might reduce the number of depressive episodes but increase the number of manic episodes that occur. Perhaps consideration of the nature of the most recent episode would help prediction sufficiently to justify such prophylaxis.