Compare intramuscular (IM) ketamine to a combination of IM midazolam and haloperidol with regards to the time required for adequate behavioral control, in minutes, in patients presenting to the emergency department with psychomotor agitation and violent behavior.

Inclusion Criteria:

1. Age 19 - 60 years inclusively;
2. Patients presenting to the emergency department with psychomotor agitation or violent behaviour (RASS score > +3).

Exclusion Criteria:

1. Less than 19 years of age;
2. Greater than 60 years of age;
3. Previous participation in this study;
4. Women suspected or known to be pregnant or breastfeeding;
5. Previous known hypersensitivity, intolerance or allergy to ketamine, midazolam or haloperidol or their components.
6. Subjects who are in comatose states or have CNS depression due to alcohol or are taking other depressant drugs.
7. Subjects with severe depressive states, spastic diseases and in Parkinson's syndrome, except in the case of dyskinesias due to levodopa treatment.
8. Senile patients with pre-existing Parkinson-like symptoms.
9. Subjects with a history of cerebrovascular accident
10. Subjects in whom a significant elevation of blood pressure would constitute a serious hazard, such as patients with significant hypertension
11. Subjects with severe cardiac decompensation
12. Subjects who intend to have surgery of the pharynx, larynx, or bronchial tree unless adequate muscle relaxants are used
13. Subjects with acute pulmonary insufficiency
14. Subjects with severe chronic obstructive pulmonary disease
15. Subjects with acute narrow angle glaucoma