New Insights on Neurocognition in Cocaine Use Disorder

Differential large-scale network functional connectivity in cocaine-use disorder associates with drug-use outcomes

Cocaine-use disorder (CUD) affects both structure and function of the brain. A triple network model of large-scale brain networks has been useful for identifying aberrant resting-state functional connectivity (rsFC) associated with mental health disorders including addiction. The present study investigated differences between people with CUD vs. controls (CONs) and whether putative differences were associated with drug-use outcomes. Participants with CUD (n = 38) and CONs (n = 34) completed a resting functional magnetic resonance imaging (fMRI) scan. Participants with CUD completed several mental health measures and participated in an 8-week, drug-use outcomes phase. A classification framework based on the triple network model was built, and triple networks (salience [SN], executive control [ECN], default mode [DMN]) and subcortical (striatum [ST], hippocampus/amygdala) regions were identified with the algorithm of group-information-guided independent components analysis (GIG-ICA) and subsequent support-vector machines. This classifier achieved 77.1% accuracy, 73.8% sensitivity, and 80.0% specificity, with an area under the curve of 0.87 for distinguishing CUD vs. CON. The two groups differed in SN-anterior DMN (aDMN) and ECN-aDMN rsFC, with the CUD group exhibiting stronger rsFC compared to CONs. They also differed in rsFC between several subcortical and triple networks, with CUD generally showing a lack of rsFC. Within the CUD group, ST-aDMN and ST-rECN rsFC were associated with differential drug-use outcomes. Exploratory results suggested SN-aDMN rsFC was associated with anxiety symptoms. These results add to the growing literature showing aberrant triple network and subcortical rsFC associated with substance use disorders. They suggest the aDMN specifically may underlie important differences between people with CUD and CONs and may be a potential target for intervention.

Structural and functional pathology in cocaine use disorder with polysubstance use: A multimodal fusion approach structural-functional pathology in cocaine use disorder

Cocaine use disorder (CUD) is described as a compulsive urge to seek and consume cocaine despite the inimical consequences. MRI studies from different modalities have shown that CUD patients exhibit structural and/or functional connectivity pathology among several brain regions. Nevertheless, both connectivities are commonly studied and analyzed separately, which may potentially obscure its relationship between them, and with the clinical pathology. Here, we compare structural and functional brain networks in CUD patients and healthy controls (HC) using multimodal fusion. The sample consisted of 63 (8 females) CUD patients and 42 (9 females) healthy controls (HC), recruited as part of the SUDMEX CONN database. For this, we computed a battery of graph-based measures from multi-shell diffusion-weighted imaging and resting state fc-fMRI to quantify local and global connectivity. Then we used multimodal canonical component analysis plus joint independent component analysis (mCCA+jICA) to compare between techniques and evaluate group differences and its association with clinical alteration. Unimodal results showed a striatal decrease in the participation coefficient but applied supervised data fusion revealed other regions with cocaine-related alterations in joint functional communication. When performing multimodal fusion analysis, we observed a higher centrality of the interrelationship and a lower participation coefficient in patients with CUD. In contrast to the unimodal approach, the multimodal fusion method was able to reveal latent information about brain regions involved in impairment due to cocaine abuse. The present results could help in understanding the pathology of CUD to develop better pre-treatment/post-treatment intervention designs.

Unpacking common and distinct neuroanatomical alterations in cocaine dependent versus pathological gambling

Pathological gambling and cocaine dependence are highly pervasive disorders. Functional neuroimaging evidence implicates aberrant activity of prefrontal striatal pathways in both disorders. It is unclear if the neuroanatomy of these areas is also affected. Participants with pathological gambling (n = 18), cocaine dependence (n = 19) and controls (n = 21) underwent high-resolution structural MRI scan and cognitive assessments. In line with emerging functional neuroimaging findings, we hypothesised (i) lower volumes of corticostriatal areas ascribed to decision-making/inhibitory control, craving and reward processing (i.e., orbitofrontal cortex, inferior frontal gyrus, amygdala, striatum, insula) in both pathological gamblers and cocaine dependent participants versus controls; (ii) selected dopaminergic/glutamatergic pathways directly taxed by cocaine (i.e., superior, dorsolateral and anterior cingulate cortices) would be altered in cocaine dependent versus control participants only. Analyses were conducted with a bonferroni correction. Our results showed that both pathological gambling and cocaine dependent participants, compared to controls, had larger volumes of the right inferior frontal gyrus (ps <.01, ds = 0.66 and 0.62). Cocaine dependent participants had lower nucleus accumbens and medial orbitofrontal cortex volumes than pathological gamblers (ps <.05, ds = 0.51 and 0.72), with the latter being predicted by higher negative urgency scores. Inferior frontal gyrus volume may reflect common alterations of cocaine and gambling addictions, whereas cocaine dependence may be uniquely associated with reduced volume in dorsolateral and middle frontal regions. Cocaine's supra-physiological effects on mesolimbic neurons may explain reduced accumbens-orbitofrontal structure compared to gambling.