Predictors of Intravenous Ketamine Response in TRD

For patients with treatment-resistant depression (TRD), a single low dose of intravenous (IV) ketamine can help relieve symptoms as quickly as 24 hours later. The main problem with IV ketamine for TRD is that the effect is short-lived, lasting only days to 1 or 2 weeks. Furthermore, IV ketamine is a resource-intensive treatment, and the safety of long-term, repeated use for depression is unknown. To provide this treatment in a safe and cost-effective way, Investigators must allocate it efficiently to those patients who have the greatest need and probability of benefit. Therefore, this project aims to find clinical features (signs, symptoms, and parts of a patient's history) that will help predict which patients are most likely to respond to a single dose of IV ketamine for TRD. This will help guide patient selection and triaging. Investigators will recruit 40 participants with TRD, and randomize them to one of two conditions (ketamine followed by an active placebo 3-weeks later, or vice versa). With clinical data collected through detailed interviews, questionnaires, actigraphy, speech sampling, electroencephalography (EEG), and computerized tasks, this study design will let us evaluate how well such factors predict (A) rapid response at 24-hours, and (B) sustained response at 7 and 14 days.