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White matter (WM) abnormalities in patients with cocaine use disorder (CUD) have been studied; however, the reported effects on the human brain are heterogenous and most results have been obtained from male participants. In addition, biological data supporting the imaging findings and revealing possible mechanisms underlying the neurotoxic effects of chronic cocaine use (CU) on WM are largely restricted to animal studies. To evaluate the neurotoxic effects of CU in the WM, we performed an in vivo diffusion tensor imaging assessment of male and female cocaine users (n = 75) and healthy controls (HC) (n = 58). Moreover, we performed an ex vivo large-scale proteomic analysis using liquid chromatography-tandem mass spectrometry in postmortem brains of patients with CUD (n = 8) and HC (n = 12). Compared with the HC, the CUD group showed significant reductions in global fractional anisotropy (FA) (p < 0.001), and an increase in global mean (MD) and radial diffusion (RD) (both p < 0.001). The results revealed that FA, RD, and MD alterations in the CUD group were widespread along the major WM tracts, after analysis using the tract-based special statistics approach. Global FA was negatively associated with years of CU (p = 0.0421) and female sex (p < 0.001), but not with years of alcohol or nicotine use. Concerning the fibers connecting the left to the right prefrontal cortex, Brodmann area 9 (BA9), the CUD group presented lower FA (p = 0.006) and higher RD (p < 0.001) values compared with the HC group. A negative association between the duration of CU in life and FA values in this tract was also observed (p = 0.019). Proteomics analyses in BA9 found 11 proteins differentially expressed between cocaine users and controls. Among these, were proteins related to myelination and neuroinflammation. In summary, we demonstrate convergent evidence from in vivo diffusion tensor imaging and ex vivo proteomics analysis of WM disruption in CUD.

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Across numerous studies, individuals with substance use disorders (SUDs) differed from nonusing controls regarding valuation of delayed gratification and feedback processing. However, it remains unclear whether the magnitude of the effect sizes is different across these two cognitive processes and how specific SUDs as well as demographic and clinical moderators influence these effects. In this study we thus performed multilevel linear mixed-effects meta-analyses and meta-regressions to examine the effects of SUDs on the Delay Discounting Task (DD) and on the Iowa Gambling Task (IGT). We found a moderate to large effect for SUD on both, the IGT and DD. While the effect on the DD was generalized to all substance classes, a smaller effect for cannabis-related disorder when compared to other SUDs was found with regard to the IGT. Early onset of substance use and psychiatric comorbidities were associated with stronger effects on the DD. Our findings suggest that feedback processing is more vulnerable to specific substance effects, while valuation of delayed gratification depends more on developmental and clinical factors.

Despite the lack of studies and the methodological limitations of the existing ones Theory of Mind seems to play a role in drug use conditions, which requires further investigation.

Background Chronic cocaine use has been consistently associated with decision-making impairments that contribute to the development and maintenance of drug-taking. However, the underlying cognitive processes of risk-seeking behaviours observed in chronic cocaine users (CU) have so far remained unclear. Here we therefore tested whether CU differ from stimulant-naïve controls in their sensitivity to gain, loss, and probability of loss information when making decisions under risk. Method A sample of 96 participants (56 CU and 40 controls) performed the no-feedback version of the Columbia Card Task, designed to assess risk-taking in relation to gain, loss, and probability of loss information. Additionally, cognitive performance and impulsivity were determined. Current and recent substance use was objectively assessed by toxicological urine and hair analysis. Results Compared to controls, CU showed increased risk-seeking in unfavourable decision scenarios in which the loss probability was high and the returns were low, and a tendency for increased risk aversion in more favourable decision scenarios. In comparison to controls, CU were less sensitive to gain, but similarly sensitive to loss and probability of loss information. Further analysis revealed that individual differences in sensitivity to loss and probability of loss information were related to cognitive performance and impulsivity. Conclusion Reduced sensitivity to gains in people with CU may contribute to their propensity for making risky decisions. While these alterations in gain sensitivity might directly relate to cocaine use per se, the individual psychopathological profile of CU might moderate sensitivity to loss information.

Adult female crack cocaine users and female adolescents took similar risks during risky decision-making scenarios where feedback about their own performance was absent. However, when participants were provided with such feedback, it modulated risk-taking behaviors in crack cocaine users but not in adolescents.

Objective: To translate and adapt to Brazilian Portuguese the Revised Reading the Mind in the Eyes Test (RMET), in both paper-and-pencil and computerized versions. The RMET is a well-accepted instrument for assessment of Theory of Mind (ToM), an important component of social cognition. Methods: Following a guideline for translation of material for clinical populations, this study had three main phases: 1) formal translation and semantic adaptation to Brazilian Portuguese; 2) an acceptability trial with health professionals as judges evaluating picture-word matching; and 3) a trial using the paper-and-pencil and computerized versions (experiments built in E-Prime 2.0.10 software) with healthy participants to test whether the instrument has similar outputs to those expected in versions in other languages. Results: RMET was adequately adapted to Brazilian Portuguese. This version showed acceptability and outputs similar to versions of the instrument in other languages, including the original one. We kept the same number of images as the original English version. Conclusions: Considering the scarcity of cognitive assessment instruments adequately adapted to Portuguese and the importance of social cognition in many psychiatric disorders, this work adds an important resource to Brazilian research and is administrable in both paper-and-pencil and computerized versions.