C. Cariprazine (Vraylar) is FDA-approved for schizophrenia and mania, and it also has positive placebo-controlled data in bipolar depression and as an adjunct to antidepressants in unipolar depression. It differs from the others in that it is more potent at dopamine D3 receptors than at D2 receptors.
Dopamine plays an important role in controlling motor behavior, the emotional reward, and behavior motivation mechanisms. It regulates emotional responses, hormone secretion, and motoric actions...
Excess dopamine receptors and a hyperactive reward process network may underly the manic phase of the condition. Meanwhile, decreases in levels of a substance called dopamine transporter may contribute to lower dopamine function and depression. The overall problem may be with dopamine regulation, not simply highs or lows.  
Adults Monotherapy — The efficacy of oral olanzapine in the treatment of manic or mixed episodes was established in 2 short-term (one 3-week and one 4-week) placebo-controlled trials in adult patients who met the DSM-IV criteria for bipolar I disorder with manic or mixed episodes. These trials included patients with or without psychotic ...