ABSTRACT R01 MH076079 Neural Mechanisms of Monoaminergic Engagement in Late-Life Depression Treatment Response [NEMO] tests a mechanistic model that describes the treatment-related dynamic changes of the core cognitive and affective networks (CAN) at rest and during standard behavioral tasks as well as the moderating role of vascular burden on the association between CAN engagement and treatment response. We proposed to recruit 100 older adults with late-life depression. The award was received on January 1, 2017. Since then, we hit all the adjusted recruitment milestones until year 4, when due to the COVID pandemic we had to halt recruitment as our potential participants were in the higher-risk age group (60 and older). As of June 2021, we are at 54% of projected recruitment. We project that by December 2021 (end of award), we will recruit a total of 64 participants. In order to be able to power the analyzes in both aims of the study we need to recruit at least 80 subjects. Thus, we need to recruit an additional 16 subjects during the requested additional five months of funding. This judicious target is based on the pace of recruitment during the first four years of the project. This is crucial for the successful analysis of data (based on power calculations). As we reach the end of the funding period for this study, we are planning to submit a competing continuation that would rely on the powered results from the current proposal. The requested funds are specifically aimed to recover salaries paid during shutdown. This proposal is responsive to NOT-MH-21-120 as 1) it is within the scope of the funded research; 2) NEMO is in the last year of the award; 3) completion of enrollment and follow-up are critical for the success of the current project.