Substance abuse and white matter: Findings, limitations, and future of diffusion tensor imaging research

Abstract

Individuals who abuse substances often differ from nonusers in their brain structure. Substance abuse and addiction is often associated with atrophy and pathology of grey matter, but much less is known about the role of white matter, which constitutes over half of human brain volume. Diffusion tensor imaging (DTI), a method for non-invasively estimating white matter, is increasingly being used to study addiction and substance abuse. Here we review recent DTI studies of major substances of abuse (alcohol, opiates, cocaine, cannabis, and nicotine substance abuse) to examine the relationship, specificity, causality, and permanence of substance-related differences in white matter microstructure. Across substance, users tended to exhibit differences in the microstructure of major fiber pathways, such as the corpus callosum. The direction of these differences, however, appeared substance-dependent. The subsample of longitudinal studies reviewed suggests that substance abuse may cause changes in white matter, though it is unclear to what extent such alterations are permanent. While collectively informative, some studies reviewed were limited by methodological and technical approach. We therefore also provide methodological guidance for future research using DTI to study substance abuse.

Dissecting the Fornix in Basic Memory Processes and Neuropsychiatric Disease: A Review

“…Substance abuse is a classic model of reward seeking gone awry. We recently reviewed the diffusion imaging literature on substance abuse (Hampton, Hanik, & Olson, 2019) and found that the literature was highly inconsistent, even when restricted to a particular substance like cocaine. The fornix was mentioned as being affected in only a single study of adolescents with alcohol use disorder (Cardenas et al, 2013).…”

White matter deficits in cocaine use disorder: convergent evidence from in vivo diffusion tensor imaging and ex vivo proteomic analysis

“…Although most neuroimaging studies have examined the chronic cocaine use (CU) effects on specific gray matter brain regions, several recent investigations have focused on revealing the white matter (WM) signature of CUD 7 . Diffusion-weighted imaging (DWI) is a magnetic resonance sequence that captures water diffusion properties in the brain and has been frequently used in studies that determined the fibers and tracts that are progressively deteriorated because of repeated cocaine consumption.…”

Addiction science and the perception of freewill

“…Large studies report some differences in prefrontal gray matter, with deficits associated with addicted populations (Xiao et al, 2015; Yuan et al, 2010). They also suggest deficits in the white matter tracts that provide the pathway whereby the prefrontal cortex exerts influence over subcortical signaling (Hampton, Hanik, & Olson, 2019). Other work suggests relevant neurotransmitter deficits in addicted populations, including a deficiency in dopamine projecting to the prefrontal cortex, which supports executive function (Koob & Volkow, 2010; Martinez et al, 2012; Volkow, Fowler, Wang, Baler, & Telang, 2009).…”