Brain connectivity network as a mediator in cocaine use disorder and impulsivity

• Main Author: Yuvaraj S/O Arumugam
• Other Authors: Yu Junhong
• Format: Final Year Project
• Language: English
• Published: Nanyang Technological University 2023
• Subjects: Social sciences::Psychology
• Online Access: https://hdl.handle.net/10356/168472
• Institution: Nanyang Technological University

Cocaine, as a drug, has harmful effects on the human body and has affected various populations in the world. With cocaine use disorder (CUD) being diagnosed due to prolonged use, one of the studied effects of CUD would be impulsivity. This study, therefore, aims to explore the relationship between CUD and impulsivity, while including how brain connectivity networks can influence the relationship between CUD and impulsivity. Participants and their data (MRI and impulsivity measure of the BIS-11) were attained from the SUDMEX database. Diffusion tensor imaging and resting-state functional MRI data were processed using MRtrix3 and fMRIprep, respectively, before extracting structural and functional connectivity (FC) matrices for each participant. Network-based statistics were conducted to observe whether significant differences between CUD and Healthy Control (HC) participants existed, followed by a mediation analysis, with the brain connectivity network(s) serving as a mediator. Results showed that a CUD diagnosis-positive FC network mediated the relationship between CUD and non-planning impulsivity, where a strong functional coupling was found in between the frontoparietal and default-mode network. The frontoparietal network and default-mode network are part of a larger theorized triple network model of the dysfunction, where switching between the frontoparietal network and default-mode network could be due to an abnormal salient network. No structural connectivity (SC) networks were found to be significantly associated with CUD. This study has contributed to the discovery of CUD-related biomarkers in the brain and has shown that these biomarkers are linked to observable individual differences in impulsivity.