Neurocircuitry Mechanisms and Efficacy of Lumateperone as Adjunctive Therapy for Major Depressive Disorder and History of Early Life Abuse

The purpose of this clinical research study is to understand how effective and safe an investigational study drug called lumateperone is and whether it works to reduce the severity of depressive symptoms in adults with Major Depressive Disorder (MDD) and early life trauma. The main questions it aims to answer are: Aim 1: To assess the efficacy of lumateperone 42 mg administered once daily compared with placebo in the treatment of patients with Major Depressive Disorder and early life abuse. Aim 2: To assess neurocircuitry encoding of threat and reward learning as predictors of lumateperone response and as mechanisms of treatment action, and assess the change from pre-dose to post-dose of task-evoked brain activation.