Advances in microstructural diffusion neuroimaging for psychiatric disorders

Abstract

Understanding the neuropathological underpinnings of mental disorders such as schizophrenia, major depression, and bipolar disorder is an essential step towards the development of targeted treatments. Diffusion MRI studies utilizing the diffusion tensor imaging (DTI) model have been extremely successful to date in identifying microstructural brain abnormalities in individuals suffering from mental illness, especially in regions of white matter, although identified abnormalities have been biologically non-specific. Building on DTI's success, in recent years more advanced diffusion MRI methods have been developed and applied to the study of psychiatric populations, with the aim of offering increased sensitivity to subtle neurological abnormalities, as well as improved specificity to candidate pathologies such as demyelination and neuroinflammation. These advanced methods, however, usually come at the cost of prolonged imaging sequences or reduced signal to noise, and they are more difficult to evaluate compared with the more simplified approach taken by the now common DTI model. To date, a limited number of advanced diffusion MRI methods have been employed to study schizophrenia, major depression and bipolar disorder populations. In this review we survey these studies, compare findings across diverse methods, discuss the main benefits and limitations of the different methods, and assess the extent to which the application of more advanced diffusion imaging approaches has led to novel and transformative information with regards to our ability to better understand the etiology and pathology of mental disorders.

Microstructural White Matter and Links With Subcortical Structures in Chronic Schizophrenia: A Free-Water Imaging Approach

“…Forty-four regions of interests (ROIs; Table 1) were extracted. Further, we derived the standard DTI measures of AD, RD, and mean diffusivity (MD) and projected them onto the FA skeleton for an extra level of investigation, as recommended in a recent review (39).…”

Psychopathology—a Precision Tool in Need of Re-sharpening

“…Yet, mental disorders neither exist per se nor are they distinct diagnostic entities, but commonly share features. In mental health research, however, shared features are not only problem of clinical psychopathology but also of genetics ( 32 ) and neurobiology ( 33 , 34 ).…”

In vivo human whole-brain Connectom diffusion MRI dataset at 760 μm isotropic resolution

“…Diffusion magnetic resonance imaging (dMRI) 1 has proven to be an invaluable tool in the study of brain structural connectivity and complex tissue microarchitecture. It has also offered the ability to investigate a variety of neurological, neurodegenerative and psychiatric disorders [2][3][4][5][6][7][8][9][10] . In recent years, a number of dMRI data repositories [11][12][13][14][15][16][17][18] have been published to enhance the understanding of human brain, including large-scale population study projects launched across the world, such as the Human Connectome Project (HCP) [19][20][21][22] and the UK Biobank project 23 .…”