GSK-3 activity in neocortical cells is inhibited by lithium but not carbamazepine or valproic acid.

Objectives: Lithium (Li(+)) has been suggested to target the enzyme glycogen synthase kinase 3 (GSK-3) as a mechanism of mood stabilization. Inhibition of GSK-3 by a second mood-stabilizer, valproic acid (VPA), has also been reported, but this effect is dependent on cell type. It is currently unknown if carbamazepine (CBZ) inhibits GSK-3 activity.