I 2 ud af 2 placebo- og 2 ud af 3 komparatorkontrollerede undersøgelser af mere end 2. 900 skizofrene patienter med både positive og negative symptomer blev olanzapin forbundet med statistisk signifikante større forbedringer af negative såvel som af positive symptomer.
In two of two placebo and two of three comparator controlled trials with over 2,900 schizophrenic patients presenting with both positive and negative symptoms, olanzapine was associated with statistically significantly greater improvements in negative as well as positive symptoms.