Raymond W Lam

608. Baseline Resting-State fMRI Biomarkers of Depression Response to DLPFC-rTMS: Different Patterns of Functional Connectivity Predict Response to 10 Hz rTMS and Intermittant TBS

(TBI51251, NoTBI57294). In a subsample of participants with high quality resting state fMRI data (TBI5311, NoTBI52269) we compared DMN connectivity between groups and investigated if history of TBI modulated the relationship between DMN RS-FC and internalizing symptoms. Results: Participants with a history of TBI had higher levels of internalizing symptoms than those who did not have a history of TBI. In the subset of participants who underwent functional imaging, there was no difference in DMN connectivity between groups. TBI participants displayed differential associations between DMN connectivity and levels of internalizing symptoms such that lower levels of connectivity within the DMN predicted increased symptoms in youth without a history of TBI and lower levels of connectivity between the DMN and other resting state networks predicted higher levels of internalizing symptoms in youth with a history of TBI. Conclusions: These results suggest that differential variations in within and between network DMN connectivity are related to internalizing symptoms if there is a history of TBI. Supported By: SickKids Foundation; FedEx Catalyst Scholarship