miRNAs, Suicide, and Ketamine - Plasma Exosomal microRNAs as Novel Biomarkers for Suicidality and Treatment Outcome

The purpose of this study is to examine whether neural-derived exosomal miRNAs are differentially expressed that are specific to suicidal ideation or behavior, and which by affecting specific miRNA targets and pathways, are associated with suicidal behavior and response to ketamine. The following groups of subjects will be examined: 1) major depressive disorder (MDD) with a recent suicide attempt (in past 2 weeks), 2) MDD with serious ideation (in the past 7 days) without recent suicide attempt (in the past 6 months), 3) MDD without clinically significant suicidal ideation (in the past 7 days) or recent suicide attempt (in the past 6 months), and 4) healthy controls. Both suicidal and non-suicidal MDD will be given ketamine (0.5 mg/kg, IV) and blood will be drawn at predose, 30 min, 180 min, 24 hours, and 14 days post-infusion to measure changes in miRNAs. As of May 2022, study is in data analysis. Final outcomes will be known once analysis is complete. As of July 2022, all data collection is complete. The primary and secondary data outcome measure results are complete. The investigators are working on final analysis of the mRNA samples, to provide final responses to questions posed in the Detailed Description section below and listed here: 1) whether suicidal ideation or behavior is associated with differences in the expression of specific miRNAs, 2) whether anti-suicidal/antidepressant effects of ketamine is associated with miRNAs changes, and 3) whether miRNA/mRNA-regulatory pathways contribute to suicide pathogenesis and treatment response.