Ketamine Infusion for Adolescent Depression and Anxiety

Inclusion:

MDD Cohort:

* Meet DSM-5 criteria for Major Depressive Disorder by structured interview (MINI-KID)
* CDRS-R score \>40.
* Failure to achieve remission with at least 1 adequate prior antidepressant trial (e.g. SSRI, SNRI, or TCA), meaning at least 8 weeks at therapeutic dosing, including at least 4 weeks of stable dosing.

Anxiety Cohort:

* Meet DSM-5 criteria for any of the following anxiety disorders: Social Anxiety Disorders, Generalized Anxiety Disorder, Separation Anxiety Disorder and/or Panic Disorder by structured interview (MINI-KID)
* ADIS Clinical Severity Rating ≥4 (moderately severe) for any of the 4 included anxiety disorders
* Failure to achieve remission with at least 1 adequate prior anxiolytic medication trial (e.g. SSRI, SNRI, or TCA), meaning at least 8 weeks at therapeutic dosing, including at least 4 weeks of stable dosing.
* Failure to achieve remission with previous CBT or subject declines current CBT therapy

Both cohorts:

* Stable psychiatric medications and doses for the month prior to enrollment. Subjects may continue to engage in any ongoing psychotherapy.
* Medically and neurologically healthy on the basis of physical examination and medical history.
* Parents able to provide written informed consent and adolescents must additionally provide assent.

Exclusion:

* Current inpatient hospitalization or active suicidal ideation requiring referral for inpatient hospitalization for safety.
* History of psychotic disorder or manic episode diagnosed by MINI-KID
* History of substance dependence diagnosis by MINI-KID (excluding tobacco) or positive urine toxicology.
* Pregnancy (urine pregnancy tests on the day of scans for menstruating girls).
* Inability to provide written informed consent according to the Yale Human Investigation Committee (HIC) guidelines in English.