This study will characterize insulin sensitivity in response to treatment with ALKS 3831, olanzapine, and placebo.

Inclusion Criteria:

• Body Mass Index (BMI) between 18.0 and < 25.0 kg/m^2 at screening and randomization
• No prior history of regular smoking or nicotine use
• Women of child-bearing potential should be on stable regimens of oral contraceptives for at least 2 months prior to screening
• Subjects must be willing to avoid a regular exercise regimen from screening through the end of the treatment period
• Additional criteria may apply

Exclusion Criteria:

• Has current evidence or history of any clinically significant medical or psychiatric condition or observed abnormality
• Is currently pregnant or breastfeeding, or is planning to become pregnant during the study
• Has a lifetime history of diabetes
• Has a known risk of narrow-angle glaucoma
• Has a clinically significant illness within 30 days prior to screening or admission to the clinic
• Has a history of dependence on any substance other than caffeine
• Has a current or anticipated need for prescribed opioid medication (eg, planned surgery) during the study period
• Has a positive urine drug screen for drugs of abuse at screening or admission to the study site
• Has had a serious infection (eg, pneumonia or septicemia) within the 3 months prior to screening or admission to the clinic
• Has had any vaccinations in the 4 weeks prior to screening or admission to the clinic
• Chronic use of non-steroid anti-inflammatory drugs (NSAIDs) and acetaminophen, except for low-dose Aspirin is not allowed
• Use of new prescription and non-prescription drugs, as well as dietary/nutritional supplements within 3 weeks preceding the first dosing of study drugs, unless approved by Investigator
• Has prior use of any antipsychotic medication, including on and off label uses
• Additional criteria may apply