Staffing and space deficiencies prevented completion of the study.

This study will evaluate the effect of ketamine on the treatment of patients hospitalized with suicidal thoughts. Half of the patients will receive one dose of ketamine in the vein. The other half will receive a placebo. Because we think that ketamine will improve depression and suicidal thoughts, we expect that patients who receive ketamine will require less time in the hospital than patients who receive placebo.

Patients admitted to UMMC's psychiatry inpatient unit with suicidal thoughts will be given the opportunity to participate in the study. Those patients who consent to participate, after being informed about the study and its risks, will be randomized to receive an IV infusion of either saline or ketamine 0.5 mg/kg. The infusion will be given within 24 hours of arriving on the psychiatry inpatient unit. We will record the dates and times that the patient was admitted to and discharged from the psychiatric inpatient unit. At completion of the study, we will compare the average length of stay, defined as date and time of discharge minus date of time of admission, of the group that received ketamine to the average length of stay of the group that received placebo.

Inclusion Criteria:

1. Men and women between the ages of 18 and 64
2. Patients admitted to the University of Mississippi Medical Center inpatient psychiatry service with suicidal ideations

Exclusion Criteria:

1. Lifetime history of schizophrenia or other primary psychotic disorder
2. Current psychotic or manic symptoms
3. Substance use disorder within one month of admission
4. Positive urine toxicology at admission
5. Any lifetime abuse of ketamine or phencyclidine
6. Systolic BP >180 mmHg or diastolic BP >110 mmHg
7. Any patient who has eaten food within 8 hours prior to receiving the ketamine infusion or who has drank clear liquids within 2 hours prior to receiving the infusion
8. Known central nervous system (CNS) mass
9. CNS abnormalities
10. Hydrocephalus
11. Glaucoma
12. Acute globe injury
13. Porphyria
14. Untreated thyroid disease
15. Known coronary artery disease with poor functional capacity
16. Pregnancy
17. Currently breast-feeding

We recorded adverse events that occurred during the infusion and for 30 minutes after the infusion.

The small number of subjects (i.e., only 4) recruited prior to the premature termination of this study prevents one from drawing meaningful conclusions from this data.