Disrupted brain state dynamics in opioid and alcohol use disorder: attenuation by nicotine use.

Substance use disorder (SUD) is a chronic relapsing disorder with long-lasting changes in brain intrinsic networks. While most research to date has focused on static functional connectivity, less is known about the effect of chronic drug use on dynamics of brain networks. Here we investigated brain state dynamics in individuals with opioid use (OUD) and alcohol use disorder (AUD) and assessed how concomitant nicotine use, which is frequent among individuals with OUD and AUD, affects brain dynamics. Resting-state functional magnetic resonance imaging data of 27 OUD, 107 AUD, and 137 healthy participants were included in the analyses. To identify recurrent brain states and their dynamics, we applied a data-driven clustering approach that determines brain states at a single time frame. We found that OUD and AUD non-smokers displayed similar changes in brain state dynamics including decreased fractional occupancy or dwell time in default mode network (DMN)-dominated brain states and increased appearance rate in visual network (VIS)-dominated brain states, which were also reflected in transition probabilities of related brain states. Interestingly, co-use of nicotine affected brain states in an opposite manner by lowering VIS-dominated and enhancing DMN-dominated brain states in both OUD and AUD participants. Our finding revealed a similar pattern of brain state dynamics in OUD and AUD participants that differed from controls, with an opposite effect for nicotine use suggesting distinct effects of various drugs on brain state dynamics. Different strategies for treating SUD may need to be implemented based on patterns of co-morbid drug use.

Relationship between optical coherence tomography findings and clinical variables in patients with opiate use disorder / Relação entre os achados da tomografia de coerência óptica e as variáveis clínicas em pacientes com transtorno por uso de opiáceos

ABSTRACT Purpose: This study aimed to examine optical coherence tomography findings in patients with opiate use disorder by comparing them with healthy controls. Methods: The study included 30 opiate use disorder patients and 30 controls. The participants' detailed biomicroscopic examinations, visual acuity, intraocular pressure, and both eye examinations were evaluated. A total of 120 eyes were evaluated using optical coherence tomography, measuring the central macular thickness, mean macular thickness, mean macular volume and retinal nerve fiber layer thickness. Moreover, all participants filled in the demographic data form and Barratt Impulsiveness Scale. Results: Upon examination of the optical coherence tomography findings, central macular thickness, mean macular thickness, and mean macular volume were thinner in both eyes in patients with opiate use disorder (p<0.01 in all measurements in both eyes). Similarly, the total values of the superior quadrant and retinal nerve fiber layer thickness were statistically significant in both eyes compared to that in the control group (p=0.007, p=0.002; p=0.049, p=0.007, in the right and left eyes, respectively). Only the left eye was positively correlated with retinal nerve fiber layer superior quadrant measurement and hospitalization (r=0.380, p=0.039). Conclusion: Our results revealed that the patients' central macular thickness, mean macular thickness, and mean macular volume values were thinner. Increase in the retinal nerve fiber layer thickness superior quadrant thickness and total value was also observed. Further studies with larger sampling groups that evaluate neuroimaging findings should be conducted.

RESUMO Objetivo: O objetivo foi investigar foi, os achados da tomografia de coerência óptica em pacientes com transtorno do uso de opiáceos, comparando-os com controles saudáveis. Métodos: O estudo incluiu 30 pacientes com transtorno do uso de opiáceos e 30 controles. Os exames biomicroscópicos detalhados de todos os participantes, acuidade visual, pressão intraocular e ambos os exames oculares foram avaliados com tomografia de coerência óptica. Um total de 120 olhos foram avaliados usando tomografia de coerência óptica, e a espessura macular central, espessura macular média, volume macular médio e a espessura da camada de fibra nervosa da retina dos participantes foram medidos. Além disso, todos os participantes preencheram o Formulário de Dados Demográficos e a Escala de Impulsividade Barratt (BIS-11). Resultados: Quando os achados de tomografia de coerência óptica foram examinados, espessura macular central, espessura macular média e volume macular médio eram mais finos de acordo com controles saudáveis em ambos os olhos em pacientes com transtorno do uso de opiáceos (p<0,01 em todas as medições em ambos os olhos). Da mesma forma, os valores totais do quadrante superior e espessura da camada de fibra nervosa da retina estavam mais em níveis estatisticamente significativos em ambos os olhos em comparação com o grupo controle (p=0,007, p=0,002; p=0,049, p=0,007, no olho direito e esquerdo, respectivamente). Estar internado em hospital e apenas a medida do quadrante superior da espessura da camada de fibra nervosa da retina do olho esquerdo associou-se positivamente (r=0,380, p=0,039). Conclusão: Em nossos resultados, descobrimos que os valores de espessura macular central, espessura macular média e volume macular médio dos pacientes eram mais finos. Verificamos também espessamento no quadrante superior e valor total da espessura da camada de fibra nervosa da retina. Nosso estudo deve ser apoiado por novos estudos com grupos de amostragem maiores, nos quais os achados de neuroimagem são avaliados.

Placental volume in pregnant women with opioid use: prenatal MRI assessment.

OBJECTIVE: Opioid use in pregnant women is a growing public health concern and is shown to be associated with lower infant birth weights. Placental volume changes in prior studies correlated with various maternal and fetal conditions. We aimed to identify differences between placental volumes in pregnant women with opioid use, and control pregnant women without drug use. METHODS: We prospectively recruited 27 healthy pregnant women and 17 pregnant women with opioid use disorder who were on medication-assisted treatment (MAT). All women underwent placenta/fetal MRI at 27-39 weeks gestation on a 3 Tesla MR scanner. Placental volumes were measured in a blinded fashion using a previously validated technique. Multiple linear regression was used to identify associations of placental volume with multiple maternal and fetal clinical factors. The significance threshold was set at p < .05. RESULTS: Placental volume was significantly associated with gestational age at MRI (p < .0001), fetal sex (p = .027), MAT with smoking (p = .0008), MAT with polysubstance use (p = .01), and maternal BMI (p = .032). Placental volume was not associated with opioid MAT alone in our cohort. CONCLUSION: For pregnant women on medication-assisted treatment for opioid use disorder, there was no significant difference in placental volume compared to healthy pregnant women. However, concomitant smoking and polysubstance use in the setting of medication-assisted treatment may be detrimental to placental health. To our knowledge, this is the first study assessing placental volume in opioid use on prenatal MRI. These results support the benefit of medication-assisted treatment during pregnancy; however additional studies are needed to further elucidate the impact of opioid use on placental and fetal development and postnatal outcomes.

Bouncing back: Brain rehabilitation amid opioid and stimulant epidemics.

Recent methamphetamine and opioid use epidemics are a major public health concern. Chronic stimulant and opioid use are characterized by significant psychosocial, physical and mental health costs, repeated relapse, and heightened risk of early death. Neuroimaging research highlights deficits in brain processes and circuitry that are linked to responsivity to drug cues over natural rewards as well as suboptimal goal-directed decision-making. Despite the need for interventions, little is known about (1) how the brain changes with prolonged abstinence or as a function of various treatments; and (2) how symptoms change as a result of neuromodulation. This review focuses on the question: What do we know about changes in brain function during recovery from opioids and stimulants such as methamphetamine and cocaine? We provide a detailed overview and critique of published research employing a wide array of neuroimaging methods - functional and structural magnetic resonance imaging, electroencephalography, event-related potentials, diffusion tensor imaging, and multiple brain stimulation technologies along with neurofeedback - to track or induce changes in drug craving, abstinence, and treatment success in stimulant and opioid users. Despite the surge of methamphetamine and opioid use in recent years, most of the research on neuroimaging techniques for recovery focuses on cocaine use. This review highlights two main findings: (1) interventions can lead to improvements in brain function, particularly in frontal regions implicated in goal-directed behavior and cognitive control, paired with reduced drug urges/craving; and (2) the targeting of striatal mechanisms implicated in drug reward may not be as cost-effective as prefrontal mechanisms, given that deep brain stimulation methods require surgery and months of intervention to produce effects. Overall, more studies are needed to replicate and confirm findings, particularly for individuals with opioid and methamphetamine use disorders.

Regional cerebral blood flow in opiate dependence relates to substance use and neuropsychological performance.

Neuroimaging of opiate-dependent individuals indicates both altered brain structure and function. Magnetic resonance-based arterial spin labeling has been used to measure noninvasively cerebral blood flow (i.e. perfusion) in alcohol, tobacco and stimulant dependence; only one arterial spin labeling paper in opiate-dependent individuals demonstrated frontal and parietal perfusion deficits. Additional research on regional brain perfusion in opiate dependence and its relationship to cognition and self-regulation (impulsivity, risk taking and decision making) may inform treatment approaches for opiate-dependent individuals. Continuous arterial spin labeling magnetic resonance imaging at 4 T and neuropsychological measures assessed absolute brain perfusion levels, cognition and self-regulation in 18 cigarette smoking opiate-dependent individuals (sODI) stable on buprenorphine maintenance therapy. The sODI were compared with 20 abstinent smoking alcohol-dependent individuals (a substance-dependent control group), 35 smoking controls and 29 nonsmoking controls. sODI had lower perfusion in several cortical and subcortical regions including regions within the brain reward/executive oversight system compared with smoking alcohol-dependent individuals and nonsmoking controls. Perfusion was increased in anterior cingulate cortex and globus pallidus of sODI. Compared with all other groups, sODI had greater age-related declines in perfusion in most brain reward/executive oversight system and some other regions. In sODI, lower regional perfusion related to greater substance use, higher impulsivity and weaker visuospatial skills. Overall, sODI showed cortical and subcortical hypoperfusion and hyperperfusion. Relating to neuropsychological performance and substance use quantities, the frontal perfusion alterations are clinically relevant and constitute potential targets for pharmacological and cognitive-based therapeutic interventions to improve treatment outcome in opiate dependence.

Larger corpus callosum and reduced orbitofrontal cortex homotopic connectivity in codeine cough syrup-dependent male adolescents and young adults.

OBJECTIVES: To characterize interhemispheric functional and anatomical connectivity and their relationships with impulsive behaviour in codeine-containing cough syrup (CCS)-dependent male adolescents and young adults. METHODS: We compared volumes of corpus callosum (CC) and its five subregion and voxel-mirrored homotopic functional connectivity (VMHC) in 33 CCS-dependent male adolescents and young adults and 38 healthy controls, group-matched for age, education and smoking status. Barratt impulsiveness scale (BIS.11) was used to assess participant impulsive behaviour. Abnormal CC subregions and VMHC revealed by group comparison were extracted and correlated with impulsive behaviour and duration of CCS use. RESULTS: We found selective increased mid-posterior CC volume in CCS-dependent male adolescents and young adults and detected decreased homotopic interhemispheric functional connectivity of medial orbitofrontal cortex (OFC). Moreover, impairment of VMHC was associated with the impulsive behaviour and correlated with the duration of CCS abuse in CCS-dependent male adolescents and young adults. CONCLUSIONS: These findings reveal CC abnormalities and disruption of interhemispheric homotopic connectivity in CCS-dependent male adolescents and young adults, which provide a novel insight into the impact of interhemispheric disconnectivity on impulsive behaviour in substance addiction pathophysiology. KEY POINTS: • CCS-dependent individuals (patients) had selective increased volumes of mid-posterior corpus callosum • Patients had attenuated interhemispheric homotopic FC (VMHC) of bilateral orbitofrontal cortex • Impairment of VMHC correlated with impulsive behaviour in patients • Impairment of VMHC correlated with the CCS duration in patients.

Decreased subcortical volumes in alcohol dependent individuals: effect of polysubstance use disorder.

Chronic alcohol use has widespread effects on brain morphometry. Alcohol dependent individuals are often diagnosed with comorbid substance use disorders. Alterations in brain morphometry may be different in individuals that are dependent on alcohol alone and individuals dependent on alcohol and other substances. We examined subcortical brain volumes in 37 individuals with alcohol dependence only (ADO), 37 individuals with polysubstance use disorder (PS) and 37 healthy control participants (HC). Participants underwent a structural MR scan and a model-based segmentation tool was used to measure the volume of 14 subcortical regions (bilateral thalamus, caudate, putamen, globus pallidus, hippocampus, amygdala and nucleus accumbens). Compared to HC, ADO had smaller volume in the bilateral hippocampus, right nucleus accumbens and right thalamus. PS only had volume reductions in the bilateral thalamus compared to HC. PS had a larger right caudate compared to ADO. Subcortical volume was negatively associated with drinking measures only in the ADO group. This study confirms the association between alcohol dependence and reductions in subcortical brain volume. It also suggests that polysubstance use interacts with alcohol use to produce limited subcortical volume reduction and at least one region of subcortical volume increase. These findings indicate that additional substance use may mask damage through inflammation or may function in a protective manner, shielding subcortical regions from alcohol-induced damage.

Opioid addiction changes cerebral blood flow symmetry.

Changes in regional cerebral blood flow (rCBF) due to long-term abuse of opioids such as heroin or morphine are not yet fully understood in humans. The goal of the present study was to investigate rCBF alterations in a large sample of long-term opioid addicts in comparison to healthy controls. We investigated 21 opioid-dependent subjects, who were currently abusing heroin or were enrolled in a methadone or morphine maintenance program, and 36 healthy controls with (99m)Tc-HMPAO single photon emission computed tomography. We found a decrease in rCBF in most regions of interest in patients in comparison to controls. Long-term opioid dependence seems to decrease prefrontal CBF in particular. A right-greater-than-left CBF asymmetry in healthy subjects was reversed in patients. This change in CBF symmetry could reflect the different emotional status of opioid-dependent patients. Our findings are in line with neuropsychological investigations indicating a correlation of mood states with lateralization of hemispheric activation patterns.