Jiajia Zhu1, Yu Zhang2, Biao Zhang1, Ying Yang1, Yajun Wang1, Cun Zhang1, Wenming Zhao1, Dao-Min Zhu3, Yongqiang Yu4. 1. Department of Radiology, The First Affiliated Hospital of Anhui Medical University, Hefei 230022, China. 2. Department of Sleep Disorders, Hefei Fourth People's Hospital, Hefei 230022, China; Anhui Mental Health Center, Hefei 230022, China. 3. Department of Sleep Disorders, Hefei Fourth People's Hospital, Hefei 230022, China; Anhui Mental Health Center, Hefei 230022, China. Electronic address: hfsyzdm7778@163.com. 4. Department of Radiology, The First Affiliated Hospital of Anhui Medical University, Hefei 230022, China. Electronic address: cjr.yuyongqiang@vip.163.com.
Abstract
BACKGROUND: A variety of functional metrics derived from resting-state functional magnetic resonance imaging (rs-fMRI) have been employed to explore spontaneous brain activity changes in major depressive disorder (MDD) and have enjoyed significant success in unraveling the neurobiological mechanisms underlying this disorder. However, it is unclear whether spatial and temporal coupling relationships among these rs-fMRI metrics are altered in MDD. METHODS: 50 patients with MDD and 36 well-matched healthy controls underwent rs-fMRI scans. A dynamic analysis was applied to compute multiple frequently used metrics including fractional amplitude of low frequency fluctuations, regional homogeneity, voxel-mirrored homotopic connectivity, degree centrality and global signal connectivity. Kendall's W was used to calculate volume-wise (across voxels) and voxel-wise (across time windows) concordance among these metrics. Inter-group differences in the concordance and their associations with clinical and cognitive variables were tested. RESULTS: Compared to healthy controls, patients with MDD showed decreased whole gray matter volume-wise concordance. Despite similar spatial distributions, quantitative comparison analysis revealed that MDD patients exhibited reduced voxel-wise concordance in multiple cortical and subcortical regions. Moreover, the lower concordance was associated with worse performances in prospective memory and sustained attention in the MDD group. LIMITATIONS: The study design of fairly modest sample size did not allow us to perform a full analysis of the potential effects of medication and illness duration. CONCLUSIONS: Our findings suggest that spatial and temporal decoupling of multiple resting-state brain activity metrics may help elucidate the neural mechanisms of cognitive deficits in depression.
BACKGROUND: A variety of functional metrics derived from resting-state functional magnetic resonance imaging (rs-fMRI) have been employed to explore spontaneous brain activity changes in major depressive disorder (MDD) and have enjoyed significant success in unraveling the neurobiological mechanisms underlying this disorder. However, it is unclear whether spatial and temporal coupling relationships among these rs-fMRI metrics are altered in MDD. METHODS: 50 patients with MDD and 36 well-matched healthy controls underwent rs-fMRI scans. A dynamic analysis was applied to compute multiple frequently used metrics including fractional amplitude of low frequency fluctuations, regional homogeneity, voxel-mirrored homotopic connectivity, degree centrality and global signal connectivity. Kendall's W was used to calculate volume-wise (across voxels) and voxel-wise (across time windows) concordance among these metrics. Inter-group differences in the concordance and their associations with clinical and cognitive variables were tested. RESULTS: Compared to healthy controls, patients with MDD showed decreased whole gray matter volume-wise concordance. Despite similar spatial distributions, quantitative comparison analysis revealed that MDDpatients exhibited reduced voxel-wise concordance in multiple cortical and subcortical regions. Moreover, the lower concordance was associated with worse performances in prospective memory and sustained attention in the MDD group. LIMITATIONS: The study design of fairly modest sample size did not allow us to perform a full analysis of the potential effects of medication and illness duration. CONCLUSIONS: Our findings suggest that spatial and temporal decoupling of multiple resting-state brain activity metrics may help elucidate the neural mechanisms of cognitive deficits in depression.