The addition of olanzapine to valproate or lithium improves both depressive and manic symptoms in patients with bipolar disorder, according to a new study presented at the 153rd Annual Meeting of the American Psychiatric Association [Chicago, US; May 2000]. Researchers from Eli Lilly said that while it is well known that olanzapine is effective as monotherapy, it is important to understand how the drug works in combination with other mood stabilisers, as many patients in the 'real world' are on combination therapy.