Olanzapine reduces mania more effectively than divalproex, but has more adverse effects.

Participants 248 adults hospitalised with acute bipolar manic or mixed episodes, with or without psychotic features (confirmed with Structured Clinical Interview for DSM-IV and minimum score of 20 on the Young Mania Rating Scale at both screening and randomisation); mean age 41 years (range 18–75); 57% women. Exclusion criteria were unstable or serious medical illness; DSM-IV drug or alcohol dependence within 30 days; history of intolerance to study drugs, and treatment with lithium, anticonvulsants or antipsychotics within 24 hours of randomisation.