Additional Study Information: You are being asked to participate in this research study because you have a diagnosis ofschizophrenia. Participation is completely voluntary. The purpose of this study is to compare weight gain in participants taking ALKS 3831 olanzapine (also known as Zyprexa ) and samidorphan together, in a bi-layer tablet (meaning both medications are together in one tablet) versus participants taking only olanzapine. If you are currently on an antipsychotic medication, this study replaces your current antipsychotic with study drug (either ALKS 3831 or olanzapine).