Pharmacology - How do mood stabilizers work?

[wellhelm]

Especially lithium if possible(in that its not a anticonvulsant like your run of the mill mood stabilizer). I either can not find it or I don't understand but, in laymans terms, could one explain the mechanism of mood stabilizers in the brain? What transmitters they work off etc..

[Jatelka]

With regards to lithium: It's mode of action is unknown. Some studies have shown that it alters sodium transport in nerve cells, but how this relates to it's mood stabilising effect is anyone's guess.

The majority of other drugs used for mood stabilisation were originally developed as anti-convulsants: Things like Sodium Valproate, Gabapentin, Carbamazepine etc.

Sodium Valproates mode of action is unknown, but it is thought that it exerts it's anti-convulsant effect by modulating GABA-nergic neurotransmission, whether or not that is the case for it's mood-stabilisation effects is not known.

Gabapentin is thought to exert it's anti-convulsant activity via GABA (hence the name), but again, the exact mode of action is not known.

And guess what? Carbamazepine's mode of action isn't precisely known either! In epilepsy it is thought to reduce the excitability of nerve cells and prevent electrical impulses spreading. It isn't known how it does that.