At the 1990 LLI Physicians' Conference Robert Roberts MD,PhD, Chair of the 1988-89 AAP Committee on Drugs stated that the breastfeeding mother should be able to take lithium with careful monitoring. There's another article by Schou (1990) that supports this view (both cites are in riordan & auerbach book, 1993.) Many years ago I monitored a bfing mom on lithium. The baby was fine and we did serum levels on the babe and found very tiny amounts. All of this is based on the assumption that the mother is taking lithium for a short period ot time.