The study by [Bowden CL, Calabrese JR] et al has undoubtedly had an impact on the use of lithium in the United States.3 It compared the efficacy of valproic acid (semisodium valproate, divalproex), lithium, and placebo as prophylactic treatment in 372 patients over 52 weeks after a manic episode. Valproate was found to be better than lithium in terms of a longer duration of successful prophylaxis and less deterioration in depressive symptoms.