Optimized Predictive Treatment In Medications for Unipolar Major Depression (OPTIMUM-D)

This is a multi-site, randomized study with two treatment phases: a double-blind primary treatment phase of 8 weeks, and an open-label secondary extension phase of 4 weeks. This study aims to test a predictive biomarker algorithm to select medication treatment for patients with major depressive disorder (MDD) based on results from the recently completed Canadian Biomarker Integration Network in Depression (CAN-BIND)-1 study. This will be accomplished through collection of clinical, neurophysiological, and molecular measures from both MDD patients and healthy controls. This is not a study to evaluate efficacy of medications; medications in this study have been approved by Health Canada and are widely used for the treatment of MDD. In this study, individuals diagnosed with MDD in a current major depressive episode (MDE) will be randomly assigned to one of the two treatment groups: Personalized Assignment group or Random Assignment group. Patients in the Random Assignment group will randomly receive open-label escitalopram with the addition of either blinded placebo or brexpiprazole for 8 weeks. Patients in the Personalized Assignment group will receive open-label escitalopram with the addition of either placebo or blinded brexpiprazole for 8 weeks depending on what the predictive biomarker algorithm suggests. At Week 8, participants will be assessed for treatment response (defined as a ≥50% reduction in Montgomery Asberg Depression Rating Scale score). All patients who initially received both open-label escitalopram and blinded brexpiprazole (regardless of treatment group) will continue to receive these medications for another 4 weeks but the brexpiprazole will no longer be blinded. For those patients who initially received open-label escitalopram and blinded placebo (regardless of treatment group), nonresponders will receive open-label escitalopram and open-label brexpiprazole for another 4 weeks and responders will receive open-label escitalopram only for another 4 weeks. Over the 12 weeks, participants will attend 7 study visits where they will complete clinical assessments (clinician administered and self-report) and cognitive tests; provide blood, urine, and stool samples; undergo neuroimaging procedures (MRI and EEG); and provide speech samples. At the end of the study, modeling methods will be used to integrate data from these measures to determine the features that best predict treatment outcome.