Ketamine for Preventing Depression in Patients Undergoing Treatment for Pancreatic or Head and Neck Cancers

This is a prospective, single center, double blind, randomized, two-arm feasibility study of oral ketamine versus placebo for the prevention of depression in non-depressed patients with head and neck or pancreatic cancer undergoing curative intent cancer therapy. Approximately 40 patients with head and neck cancer or pancreatic cancer about to undergo cancer therapy will be randomized 1:1 to receive study treatment with one of the following regimens: * Arm A: weekly oral administration of 0.5 mg/kg ketamine * Arm B: weekly oral administration of placebo Consenting patients will undergo screening procedures, and if eligible, a baseline interview and brief questionnaires regarding depression, mental and emotional health, and quality of life assessments. Study treatment will be administered for 12 weeks unless the patient experiences unacceptable toxicities, exhibits moderate to severe depressive symptoms, or withdraws consent. Patients on the placebo treatment arm will not be eligible to cross over to the ketamine arm at evidence of depression but will be removed from the study and treated with standard medical management for depression. Patients will be asked to complete psychosocial measurements every two weeks, before study medication/placebo administration, while on study treatment and monthly during a five-month follow-up period.