Low-Dose Intravenous Ketamine for Adolescents With Depression and Suicidal Ideation in the Emergency Department

Inclusion Criteria: * Determined, based upon medical and social work evaluation, to require inpatient psychiatric admission without further need for medical diagnostic evaluation and treatment. * Treatment-resistant depression (defined as failure of response to trials of at least 2 antidepressant courses, each of at least 4 weeks' duration) * Parent/guardian available for consent (in person or by phone) Exclusion Criteria: * Any of the following co-existing diagnoses: primary psychotic disorder (schizophrenia, schizoaffective) autism spectrum disorder, developmental delay/intellectual disability, substance abuse disorder within the last 6 months * Aggressive behavior, homicidal ideation * Altered mental status * Pregnancy or breastfeeding, * Currently receiving (or receipt within last 24 hours) medication acting on NMDA receptor system (lamotrigine, dextromethorphan, methadone, clarithromycin, amantadine) * Incomplete medical evaluation or stabilization * Contraindications to or anaphylaxis or prior adverse reaction to Ketamine * No caregiver available * In custody of a law enforcement agency