According to a recently published study, Journal of Psychiatry Research Men with cocaine use disorder have been found to have impaired brain connectivity. The study found that men with cocaine use disorder have increased brain connectivity and persistence in certain states, particularly in the default mode network, cognitive control network, and sensorimotor network. This increased connectivity was associated with increased impulsivity and borderline personality traits, suggesting impairments in self-regulation and emotion processing.
Cocaine use disorder affects millions of people worldwide, resulting in serious health and social consequences. Despite its prevalence, effective treatments are limited, in part due to a poor understanding of the neurological underpinnings of the disorder.
While previous studies have looked at static brain connectivity, this study aimed to investigate dynamic, time-changing patterns of brain connectivity in people with cocaine use disorder. By identifying these patterns, the researchers hope to elucidate specific neural mechanisms that may inform better treatments and interventions for this challenging condition.
The research team used data from the SUDMEX CONN dataset, which contains resting-state functional magnetic resonance imaging (rs-fMRI) scans of patients diagnosed with cocaine use disorder. The study involved 69 right-handed men, 38 of whom were patients with cocaine use disorder and 31 were healthy controls. Participants with cocaine use disorder were selected based on strict criteria, including recent regular cocaine use, to ensure a clear distinction from occasional users.
To process the MRI data, the researchers employed advanced techniques to increase the quality and accuracy of measurements. Functional connectivity was analyzed using group spatial independent component analysis (ICA), which helps identify independent networks in the brain. The dynamic nature of FC was captured by a sliding window technique that examines changes in connectivity over time, rather than assuming that connectivity is constant. This approach allowed the researchers to identify distinct connectivity states through which the brain cycled during the scanning period.
The study revealed two major connectivity states: strongly connected and weakly connected. The strongly connected state was more prevalent and lasted longer in participants with cocaine use disorder compared to healthy controls. In this state, there was increased connectivity within and between multiple brain networks, including the default mode network (DMN), cognitive control network (CCN), and sensorimotor network (SMN). This increased connectivity, particularly within the DMN, suggests disruptions to processes such as self-referential thinking and emotion regulation, which are important for understanding the compulsive nature of cocaine addiction.
Furthermore, the study revealed that increased connectivity between the CCN and SMN may indicate a reorganization of brain functions related to cognitive control and motor responses. This reorganization may impair decision-making and self-control, contributing to the heightened impulsivity seen in individuals with cocaine use disorder. The researchers also found enhanced connectivity between the visual information network (VIS) and other networks, suggesting heightened sensitivity to visual stimuli. This may lead to increased reactivity to drug stimuli, further exacerbating the addiction cycle.
In addition to these state-dependent changes, the study found correlations between abnormal connectivity patterns and clinical measures of impulsivity and borderline personality traits. For example, in the strongly connected state, connectivity between the orbital portion of the inferior frontal gyrus and the fusiform/middle occipital gyrus was negatively correlated with motor impulsivity scores. This finding supports previous research showing that disruptions in these brain regions contribute to impulse control deficits in substance use disorders.
Although this study provides valuable insights into the dynamic brain connectivity of people with cocaine use disorder, several limitations should be noted. The study included only male participants, making it difficult to generalize the findings to women. Furthermore, the cross-sectional design of this study means that causal inferences cannot be made about the connectivity patterns observed. Longitudinal studies are needed to determine whether these connectivity changes precede or are a consequence of cocaine use.
the study, “Disruptions of dynamic functional brain connectivity in male cocaine use disorder: Associations with hyperconnectivity, tendency to highly connected states, impulsivity, and borderline personality traits.” authors are Zhaoyang Cong, Lin Yang, Ziyang Zhao, Guowei Zheng, Cong Bao, Pengfei Zhang, Jun Wang, Weihao Zheng, Zhijun Yao, and Bin Hu.
