Study to Evaluate the Efficacy of ALKS 3831 on Body Weight in Young Adults Who Have Been Recently Diagnosed With Schizophrenia, Schizophreniform, or Bipolar I Disorder

In the US adolescent subjects starting at age 16 will be enrolled. In the EU, subjects age 18
and older will be enrolled.

Inclusion Criteria:

- Has less than 16 weeks previous treatment with antipsychotics (cumulative; lifetime)

- Subject treated with aripiprazole can receive an additional 1 year of treatment
at ≤5 mg/day, and this treatment will not be considered as part of the 16 weeks
of previous treatment with antipsychotics

- Has less than 4 years elapse since the initial onset of active-phase of symptoms

- Has a body mass index (BMI) of <30 kg/m^2

- Agrees to use an acceptable method of contraception for the duration of the study and
for 30 days after the last dose of study drug

- Subject meets the criteria for a primary diagnosis of schizophrenia, schizophreniform
disorder, or bipolar I disorder

- For bipolar I disorder, must have experienced an episode of acute mania within ≤14
days prior to Visit 1

- Suitable for outpatient treatment

- Additional criteria may apply

Exclusion Criteria:

- Poses a current suicide risk

- Has a history of poor or inadequate response to treatment with olanzapine

- Has previously been treated with long-acting injectable antipsychotic medication or
has received treatment with electroconvulsive therapy in their lifetime

- Has initiated treatment with mood stabilizers (eg lithium, valproate, etc) >14 days
prior to Visit 1

- Has a positive drug screen for opioids, phencyclidine (PCP),
amphetamine/methamphetamine, or cocaine

- Has taken opioid agonists (eg, codeine, oxycodone, tramadol, morphine) within the 14
days prior to Visit 1, or has taken opioid antagonists, including naltrexone and
naloxone, within 60 days prior to Visit 1

- Taking any weight loss agents or hypoglycemic agents

- Has a clinically significant or unstable medical illness, condition, or disorder that
would be anticipated to potentially compromise subject safety or adversely affect the
evaluation of efficacy

- Has joined a weight management program or had significant changes in diet or exercise
regimen within the past 6 weeks

- Has started a smoking cessation program within the past 6 months

- Has a history of diabetes

- Currently pregnant or breastfeeding or is planning to become pregnant during the study
or within 30 days of the last study drug administration

- Additional criteria may apply