Canadian Biomarker Integration Network for Depression (CAN-BIND) - Validation Study

This is a multi-site study to replicate a previous multi-site, multi-platform study completed by the Canadian Biomarker Integration Network in Depression (CAN-BIND). This study aims to validate the integrated array of markers of response and non-response to first line antidepressant treatments that were previously identified in the original aforementioned study. This will be accomplished through collection of clinical, neurophysiological, and molecular measures. 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 treated with open-label escitalopram for 8 weeks. At week 8, participants will be assessed for treatment response (defined as a ≥50% reduction in Montgomery Asberg Depression Rating Scale score). Responders will continue on escitalopram for 8 more weeks. Non-responders will be given add-on brexpiprazole treatment, in addition to escitalopram, for 8 weeks. Over the 16 weeks, pariticipants will attend 7 clinical 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.