Oral Aspirin + Ketamine as Adjunct to Oral Antidepressant Therapy for Depression

Inclusion Criteria:

* Adult patients with Treatment Resistant Depression with Montgomery-Asberg Depression Rating Scale score \>22 upon presentation to the clinic
* Treatment Resistant Depression is defined as Major Depressive Disorder that does not cease after at least 6 week trial of another class of antidepressants
* Unipolar Depression

Exclusion Criteria:

* Adult patients with recent or current suicidal ideation with an intent to act, homicidal ideations with an intent to act
* History of Bipolar Disorder, Obsessive Compulsive Disorder, antisocial personality disorder, borderline personality disorder, and congestive cardiac failure
* Uncontrolled hypertension (BP \>140 mm Hg systolic and/or \>90 mm Hg diastolic on two separate readings at the time of screening) or on 2 medications for hypertension
* Patients with unstable vital signs (systolic blood pressure \<90 or\>160 mm Hg, pulse rate \<50 or \>150 beats/min, and respiration rate \<10 or \>30 breaths/min),
* History of Gastrointestinal hemorrhage, renal and hepatic insufficiency
* Allergy to Ketamine or Aspirin
* Active Substance Abuse Disorder
* Active psychosis
* Active Peptic Ulcer Disease
* Lithium Therapy
* Swallowing difficulty
* Consumption of Aspirin or NSAID's within 6 hours of arrival to the site
* Previous participation in this study; a patient may not re-enroll in another study while in this study
* Pregnant or breastfeeding