This study deals with the possible molecular mechanisms that underlie the etiology of bipolar
disorders (BD). Previous studies have implicated Na+, K+-ATPase and endogenous digitalis-like
compounds (DLC) in the depressive state of this disease. The possibility, however, that they
are also involved in the manic phase of the disease was never addressed. The results of this
study may have significant implications for the treatment of BD by DLC derivatives.