Brain imaging and substance use disorders : Focus on white matter microstructural integrity

This article describes recent studies that use Diffusion Tensor Imaging to examine white matter (WM) integrity in people with Substance Use Disorders (SUDs) on alcohol, cannabis, stimulants and opiates compared to controls. There is emerging evidence that people with SUD have altered integrity of several WM tracts that connect key regions of the reward circuit e.g., corpus callosum, internal/external capsule, thalamic radiation and longitudinal fasciculi. Results from correlational analyses showed that reduced WM integrity was associated with chronicity of use (e.g., earlier age of onset, greater duration and dosage) and improved with longer abstinence. However, the evidence to date is still sparse and highlights the need for future longitudinal studies in larger and better-characterized samples to better understand the temporal and causal relationship between WM integrity and SUD.