The Geodon acts as both an antipsychotic and an antimanic and helps to temper any possible mania from the Lexapro, so in that regard, it is somewhat of a mood stabilizer, just not your more common Lithium or anticonvulsant. And I agree, 320 mg is a huge dose - I'd be sound asleep, too. I had a hard enough time staying awake on 160 mg a day.

Why does your husband think it's not working? What kind of symptoms are you experiencing?