This study will evaluate the long-term safety, tolerability, and durability of treatment effect of ALKS 3831 in subjects with schizophrenia, schizophreniform disorder, or bipolar I disorder

Inclusion Criteria:

• Willing and able to give informed consent/assent as per local requirements
• Agrees to use an acceptable method of contraception during the study, and for 30 days after any study drug administration, unless surgically sterile or post-menopausal
• Has the potential to benefit from the administration of ALKS 3831, in the opinion of the investigator
• Subject met the eligibility criteria of the antecedent study at the time of enrollment in the antecedent study and completed the treatment period in one of the following antecedent studies within 7 days: ALK3831-A304, ALK3831-A306, or ALK3831-A307
• Additional criteria may apply

Exclusion Criteria:

• Has any finding that, in the view of the investigator or medical monitor, would compromise the safety of the subject or affect their ability to fulfill the protocol visit schedule or visit requirements
• Has a positive drug screen for drugs of abuse at study entry
• 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