Peripartum Participants:
Inclusion Criteria
* Cesarean delivery
* Adults 18 years and older
* Term delivery ≥ 37 weeks gestation anticipated at time of delivery
* ASA PS 2 or 3
* Able to provide informed consent
* One of the following must be met for inclusion: Not planning to breastfeed OR ketamine use indicated for pain management plan.
Exclusion Criteria
* Patient going under general anesthesia for cesarean delivery
* Allergy to study medication (ketamine)
* ASA PS 4 +
* Contraindications to neuraxial anesthesia
* Preterm delivery (\<37 weeks gestation)
* Anticipated fetal-neonatal complex care plan as indicated in the patient's chart
* Patient history of ketamine or PCP abuse
* Patient history of schizophrenia or psychosis
* Patient history of liver or renal insufficiency
* Patient history of uncontrolled hypertension, chest pain, arrhythmia, head trauma, or intracranial hypertension, uncontrolled hyperthyroidism, or other contraindications to ketamine
* Participating in another pain or depression intervention trial
* Undergoing hormonal or gender affirming therapies
* Pre-eclampsia with severe features
* Hemodynamic instability
* Inability to participate in study procedures for any reason
* Contraindicated medications use: oral antihypertensive medications (exclusion: hypertensive disorders of pregnancy), intravenous magnesium (exclusion: pre-eclampsia with severe features), ketamine/phencyclidine/psilocybins/any other psychedelics (exclusion: ketamine or PCP abuse), lithium/valproate/carbamazepine/lamotrigine/haloperidol/chlorpromazine/fluphenazine/aripiprazole/clozapine/other typical or atypical antipsychotic medications (exclusion: schizophrenia or psychosis)
Control Participants
Inclusion Criteria
* Age 18 years and older
* Sex: Male or Female
* Able to provide informed consent
* ASA PS 1, 2, or 3
Exclusion Criteria
* Allergy to study medication (ketamine)
* ASA PS 4 +
* Inability to participate in study procedures for any reason
* Patient history of ketamine or PCP abuse
* Patient history of schizophrenia or psychosis
* Patient history of liver or renal insufficiency
* Patient history of uncontrolled hypertension, chest pain, arrhythmia, head trauma, intracranial hypertension, uncontrolled hyperthyroidism, or other contraindications to ketamine
* Participating in another pain or depression intervention trial
* Hemodynamic instability
* Pregnant or pregnant within the last 6 weeks
* Unwilling to provide urine sample for pregnancy testing (female controls)
* Undergoing hormonal or gender affirming therapies
* Contraindicated medications use: ketamine, phencyclidine, psilocybins, or other psychedelics (exclusion: ketamine or PCP abuse), lithium/valproate/carbamazepine/lamotrigine/haloperidol/chlorpromazine/fluphenazine/aripiprazole/clozapine, or other typical or atypical antipsychotic medications (exclusion: schizophrenia or psychosis)