The purpose of this study is to assess the efficacy and safety of intramuscular olanzapine for the treatment of acute agitation associated with schizophrenia and bipolar I mania.

Inclusion Criteria:

1. Male and female patients between the ages of 18 to 65 years, inclusive.
2. Patients who have met DSM-5 criteria for schizophrenia and bipolar I disorder.
3. Patients who are judged to be clinically acutely agitated with a total score of ≥ 14 on the 5 items comprising the PANSS-EC and at least one individual item score≥ 4 immediately before randomization.

Exclusion Criteria:

1. Patients with agitation caused by delirium, seizures, developmental delay, poisoning, etc., or withdrawal from drug abuse.
2. Patients who have had previous suicidal behavior or currently at serious risk of suicide.
3. Patients with glaucoma or at risk of angle-closure glaucoma.
4. Patients who have brain diseases such as intracranial infection, brain trauma, cerebrovascular disease, basal ganglion disease, hypoxic encephalopathy, Parkinson's disease, Parkinson's syndrome, and dementia.
5. Use of benzodiazepines, other hypnotics or short-acting antipsychotic drugs within 4 hours before randomization.
6. Treatment with psychostimulants or reserpine within one week before randomization.
7. Patients who received long-acting injections of typical or atypical antipsychotics within 2 weeks prior to randomization or within one injection interval.
8. Treatment with clozapine within 4 weeks before screening.
9. Patients with serious or unstable medical illnesses.
10. Female patients who have a positive pregnancy test at screening or are breastfeeding.
11. Patients who have participated in other clinical trials within 3 months before randomization.