Methadone-induced Damage to White Matter Integrity in Methadone Maintenance Patients: A Longitudinal Self-control DTI Study

Memory function in patients with opioid dependence treated with buprenorphine and methadone in comparison with healthy persons

Methadone and buprenorphine are commonly used for drug abuse treatment but may impair cognitive function. This study assessed memory performance in patients receiving these treatments compared to healthy controls. A cross-sectional study was conducted on 93 buprenorphine- and 120 methadone-treated patients, compared with 120 healthy controls. The Wechsler Memory Scale was used, and scores were compared among the study groups using Kruskal-Wallis with Tukey's post-hoc test. Maintenance therapy duration was compared between case groups using an independent t-test or Mann-Whitney U test. Healthy controls were superior to both treatment groups in mental control. The methadone group surpassed controls in personal and general information (P < 0.05), while buprenorphine-treated patients scored lower in associate learning. Patients receiving methadone for > 2 years had a higher mean score of awareness of place and time than those on long-term buprenorphine (P = 0.034). Longer buprenorphine treatment correlated with improved total memory scores (P = 0.03). The mental test showed no significant adverse effect for either medication on most mental aspects, except for mental control, which was worse than the control group in both medications. In some aspects, treated patients even outperformed controls. Buprenorphine preserves memory function better than methadone over time.

Neuroimaging of opioid effects in humans across conditions of acute administration, chronic pain therapy, and opioid use disorder

Evidence of central nervous system (CNS) exogenous opioid effects in humans has been primarily gained through neuroimaging of three participant populations: individuals after acute opioid administration, those with opioid use disorder (OUD), and those with chronic pain receiving opioid therapy. In both the brain and spinal cord, opioids alter processes of pain, cognition, and reward. Opioid-related CNS effects may persist and accumulate with longer opioid use duration. Meanwhile, opioid-induced benefits versus risks to brain health remain unclear. This review article highlights recent accumulating evidence for how exogenous opioids impact the CNS in humans. While investigation of CNS opioid effects has remained largely disparate across contexts of opioid acute administration, OUD, and chronic pain opioid therapy, integration across these contexts may enable advancement toward effective interventions.

Structural brain changes associated with cocaine use and digital cognitive behavioral therapy in cocaine use disorder treatment

Background

Few studies have investigated changes in brain structure and function associated with recovery from cocaine use disorder (CUD), and fewer still have identified brain changes associated with specific CUD treatments, which could inform treatment development and optimization.

Methods

In this longitudinal study, T1-weighted magnetic resonance imaging scans were acquired from 41 methadone-maintained individuals with CUD (15 women) at the beginning of and after 12 weeks of outpatient treatment. As part of a larger randomized controlled trial, these participants were randomly assigned to receive (or not) computer-based training for cognitive behavioral therapy (CBT4CBT), and galantamine (or placebo).

Results

Irrespective of treatment condition, whole-brain voxel-based morphometry analyses revealed a significant decrease in right caudate body, bilateral cerebellum, and right middle temporal gyrus gray matter volume (GMV) at post-treatment relative to the start of treatment. Subsequent region of interest analyses found that greater reductions in right caudate and bilateral cerebellar GMV were associated with higher relative and absolute levels of cocaine use during treatment, respectively. Participants who completed more CBT4CBT modules had a greater reduction in right middle temporal gyrus GMV.

Conclusions

These results extend previous findings regarding changes in caudate and cerebellar GMV as a function of cocaine use and provide the first evidence of a change in brain structure as a function of engagement in digital CBT for addiction. These data suggest a novel potential mechanism underlying how CBT4CBT and CBT more broadly may exert therapeutic effects on substance-use-related behaviors through brain regions implicated in semantic knowledge.

Methadone alters transcriptional programs associated with synapse formation in human cortical organoids

Opioid use disorder (OUD) among pregnant women has become an epidemic in the United States. Pharmacological interventions for maternal OUD most commonly involve methadone, a synthetic opioid analgesic that attenuates withdrawal symptoms and behaviors linked with drug addiction. However, evidence of methadone's ability to readily accumulate in neural tissue, and cause long-term neurocognitive sequelae, has led to concerns regarding its effect on prenatal brain development. We utilized human cortical organoid (hCO) technology to probe how this drug impacts the earliest mechanisms of cortico-genesis. Bulk mRNA sequencing of 2-month-old hCOs chronically treated with a clinically relevant dose of 1 μM methadone for 50 days revealed a robust transcriptional response to methadone associated with functional components of the synapse, the underlying extracellular matrix (ECM), and cilia. Co-expression network and predictive protein-protein interaction analyses demonstrated that these changes occurred in concert, centered around a regulatory axis of growth factors, developmental signaling pathways, and matricellular proteins (MCPs). TGFβ1 was identified as an upstream regulator of this network and appeared as part of a highly interconnected cluster of MCPs, of which thrombospondin 1 (TSP1) was most prominently downregulated and exhibited dose-dependent reductions in protein levels. These results demonstrate that methadone exposure during early cortical development alters transcriptional programs associated with synaptogenesis, and that these changes arise by functionally modulating extra-synaptic molecular mechanisms in the ECM and cilia. Our findings provide novel insight into the molecular underpinnings of methadone's putative effect on cognitive and behavioral development and a basis for improving interventions for maternal opioid addiction.

Whole-brain white matter abnormalities in human cocaine and heroin use disorders: association with craving, recency, and cumulative use

Neuroimaging studies in substance use disorder have shown widespread impairments in white matter (WM) microstructure suggesting demyelination and axonal damage. However, substantially fewer studies explored the generalized vs. the acute and/or specific drug effects on WM. Our study assessed whole-brain WM integrity in three subgroups of individuals addicted to drugs, encompassing those with cocaine (CUD) or heroin (HUD) use disorder, compared to healthy controls (CTL). Diffusion MRI was acquired in 58 CTL, 28 current cocaine users/CUD+, 32 abstinent cocaine users/CUD-, and 30 individuals with HUD (urine was positive for cocaine in CUD+ and opiates used for treatment in HUD). Tract-Based Spatial Statistics allowed voxelwise analyses of diffusion metrics [fractional anisotropy (FA), mean diffusivity (MD), radial diffusivity (RD), and axial diffusivity (AD)]. Permutation statistics (p-corrected < 0.05) were used for between-group t-tests. Compared to CTL, all individuals with addiction showed widespread decreases in FA, and increases in MD, RD, and AD (19-57% of WM skeleton, p < 0.05). The HUD group showed the most impairments, followed by the CUD+, with only minor FA reductions in CUD- (<0.2% of WM skeleton, p = 0.05). Longer periods of regular use were associated with decreased FA and AD, and higher subjective craving was associated with increased MD, RD, and AD, across all individuals with drug addiction (p < 0.05). These findings demonstrate extensive WM impairments in individuals with drug addiction characterized by decreased anisotropy and increased diffusivity, thought to reflect demyelination and lower axonal packing. Extensive abnormalities in both groups with positive urine status (CUD+ and HUD), and correlations with craving, suggest greater WM impairments with more recent use. Results in CUD-, and correlations with regular use, further imply cumulative and/or persistent WM damage.

The effect of long-term methadone maintenance treatment on coupling among three large-scale brain networks in male heroin-dependent individuals: A resting-state fMRI study

PURPOSE

Methadone maintenance treatment (MMT) is considered as an effective and mainstream therapy for heroin dependence. However, whether long-term MMT would improve the coupling among the three core large-scale brain networks (salience, default mode, and executive control) and its relationship with the craving for heroin is unknown.

METHODS

Forty-four male heroin-dependent individuals during long-term MMT, 27 male heroin-dependent individuals after short-term detoxification/abstinence (SA), and 26 demographically matched healthy controls (HC) underwent resting-state functional magnetic resonance imaging. We analyzed the difference in coupling among the salience, default mode, and executive control networks among the three groups and examined how the coupling among these large-scale networks was associated with craving before and after drug-cue exposure.

RESULTS

Compared with the SA group, the MMT group showed lower craving before and after cue exposure and stronger connectivity between the dorsal anterior cingulate cortex (a key node of the salience network) and key regions of the bilateral executive control network, including the bilateral dorsolateral prefrontal cortex, posterior parietal cortex, and dorsomedial prefrontal cortex. Among the heroin-dependent individuals, the functional connectivity was negatively correlated with the craving before and after heroin-cue exposure.

CONCLUSION

Our findings suggest that long-term MMT could increase the coupling between the salience and bilateral executive control networks and decrease craving for heroin. These findings contribute to the understanding of the neural mechanism of MMT, from the perspective of large-scale brain networks.

Neurological Manifestations of Chronic Methadone Maintenance Therapy: A Case Report and Literature Review

Methadone is a long-acting opioid medication that is used as maintenance therapy for heroin addiction. We present a case of a patient on methadone maintenance therapy for chronic back pain who developed neurological complications. The patient presented with mental status changes and choreiform movements. Workup revealed lesions involving the subcortical white matter and basal ganglia. Choreiform movements improved after the initiation of treatment with topiramate, clonazepam, and risperidone. This combination was chosen as several prior case reports published significant benefit and improvement in choreiform movements with the mentioned regimen.

Assessing brain activity in male heroin-dependent individuals under methadone maintenance treatment: A resting-state fMRI study

Methadone maintenance treatment (MMT) is recognized as an effective and mainstream alternative treatment for heroin addiction. However, the effect of long-term MMT on the local and global brain activity of heroin-dependent individuals during resting state remains unknown. Twenty-five heroin-dependent individuals under MMT, 26 heroin-dependent individuals after short-term abstinence (HA) and 42 healthy controls (HC) were included in the resting-state functional magnetic resonance imaging study. The craving before and after heroin cue exposure were evaluated among HA and MMT subjects. The difference in craving, regional homogeneity (ReHo) and related functional connectivity were analyzed among the three groups. We found that the craving before and after heroin cue exposure of MMT group was significantly lower than that of HA group. Compared with HA group, the MMT group showed higher ReHo value in the right orbitofrontal cortex and bilateral posterior central cortex. No significant difference in global brain connectivity based on differential ReHo regions was found among the three groups. This study demonstrated the long-term MMT could improve the local activity of executive control and somatosensory brain regions in heroin-dependent individuals. It suggested that MMT might be beneficial to restoring executive control and somatosensory function in the direction towards that of healthy controls.

Delayed hypoxic encephalopathy: a rare complication of methadone poisoning in two cases

Methadone is a kind of opioid that is used to reduce the pain of addicts who decide to withdraw drugs. Sometimes due to a lack of appropriate cautions, this drug will be accessible to children, and poisoning might occur. Methadone poisoning usually presents with the loss of consciousness and pinpoint pupils. Herein, we present two cases of delayed hypoxic encephalopathy that had been poisoned by methadone.

Case Presentation

The first case was a 4-year-old female patient who firstly presented with nausea and vomiting; then, the case was discharged; however, 1 week later, the case was returned with the loss of consciousness and poisoning by methadone confirmed in her urine. Again 2 weeks later, the case returned to the hospital, developing weakness of limbs, slurred speech, and abnormal movement of her limbs. The second case was an 11-year-old female patient who was admitted to an intensive care unit due to the loss of consciousness and methadone poisoning. After providing supporting care, she was discharged but returned to the hospital 5 days later. She developed weakness of limbs, abnormal movement of tongue and extremities, and slurred speech. In their last admission, the magnetic resonance imaging of the patients revealed hypoxic damage in the basal ganglia; therefore, delayed hypoxic encephalopathy was confirmed.

Conclusion

Patients with methadone poisoning should be observed for at least 1 and a half months after poisoning. Moreover, parents should notice that in the case of observing abnormal neurologic manifestations bring their child as soon as possible to a hospital to prevent irreversible damage to the brain.

Time-Dependent Changes in the Serum Levels of Neurobiochemical Factors After Acute Methadone Overdose in Adolescent Male Rat

Acute methadone toxicity is a major public health concern which has adverse effects on brain tissue and results in recurrent or delayed respiratory arrest. Our study aimed to investigate the time-dependent changes in several serum biochemical markers of brain damage, spatial working memory, and the brain tissue following acute methadone overdose. Adolescent male rats underwent an intraperitoneal (i.p.) injection of 15 mg/kg methadone. In case of apnea occurrence, resuscitation was performed by a ventilatory pump and administrating naloxone (2 mg/kg; i.p.). The animals were classified into groups of treated rats; methadone and naloxone-Apnea (M/N-Apnea), M/N-Sedate, Methadone, Naloxone, and control (saline) groups. The serum levels of S100B, neuron-specific enolase (NSE), myelin basic protein factors, and (Lactate/Pyruvate) L/P ratio were evaluated at the time-points of 6, 24, and 48 h (h). We found that the alterations of S100B and L/P ratio were considerable in the M/N-Apnea and Methadone groups from the early hours post-methadone overdose, while NSE serum levels elevation was observed only in M/N-Apnea group with a delay at 48 h. Further, we assessed the spatial working memory (Y-maze test), morphological changes, and neuronal loss. The impaired spontaneous alternation behavior was detected in the M/N-Apnea groups on days 5 and 10 post-methadone overdose. The morphological changes of neurons and the neuronal loss were detectable in the CA1, striatum, and cerebellum regions, which were pronounced in both M/N-Apnea and Methadone groups. Together, our findings suggest that alterations in the serum levels of S100B and NSE factors as well as L/P ratio could be induced by methadone overdose with the presence or absence of apnea before the memory impairment and tissue injury in adolescent male rats.

Enriched Environment Ameliorates Cognitive Deficits and Locomotor Sensitization in Morphine-Withdrawn Rats Receiving Methadone Maintenance Treatment

OBJECTIVE

This study was designed to examine whether enriched environments (EE) would attenuate object recognition and spatial learning and memory deficits and locomotor sensitization induced by methadone maintenance treatment (MMT) in morphine-withdrawn rats.

METHODS

Male Wistar rats (170 ± 10 g) were injected with bi-daily doses (10 mg/kg, 12-h intervals) of morphine for 14 days. Rats receiving MMT were reared in the standard environment (SE) or EE during 30 days of morphine withdrawal. Then, the rats were tested for object recognition (the object recognition memory test, ORMT) and spatial learning and memory (the water maze) and then challenged with morphine (1 mg/kg, i.p.) and evaluated for locomotor activity (open-field box).

RESULTS

The results revealed that the dependent/saline/EE (D/Sal/EE) and D/methadone/EE (D/Meth/EE) rats exhibited significant preference for the new object (p = 0.006 and p = 0.049), spent more time in the target zone (p = 0.045 and p = 0.005) on the water maze, and displayed a lower level of distance traveled (p = 0.002 and p = 0.0001) compared to their control groups reared in SE.

CONCLUSIONS

We conclude that exposure to EE could ameliorate the object recognition and spatial memory deficits and also decrease locomotor sensitivity in morphine-withdrawn rats receiving MMT. Thus, EE may be beneficial in the treatment of addiction during MMT.

HIV-1 Tat and Morphine Differentially Disrupt Pyramidal Cell Structure and Function and Spatial Learning in Hippocampal Area CA1: Continuous versus Interrupted Morphine Exposure

About half the people infected with human immunodeficiency virus (HIV) have neurocognitive deficits that often include memory impairment and hippocampal deficits, which can be exacerbated by opioid abuse. To explore the effects of opioids and HIV on hippocampal CA1 pyramidal neuron structure and function, we induced HIV-1 transactivator of transcription (Tat) expression in transgenic mice for 14 d and co-administered time-release morphine or vehicle subcutaneous implants during the final 5 d (days 9-14) to establish steady-state morphine levels. Morphine was withheld from some ex vivo slices during recordings to begin to assess the initial pharmacokinetic consequences of opioid withdrawal. Tat expression reduced hippocampal CA1 pyramidal neuronal excitability at lower stimulating currents. Pyramidal cell firing rates were unaffected by continuous morphine exposure. Behaviorally, exposure to Tat or high dosages of morphine impaired spatial memory Exposure to Tat and steady-state levels of morphine appeared to have largely independent effects on pyramidal neuron structure and function, a response that is distinct from other vulnerable brain regions such as the striatum. By contrast, acutely withholding morphine (from morphine-tolerant ex vivo slices) revealed unique and selective neuroadaptive shifts in CA1 pyramidal neuronal excitability and dendritic plasticity, including some interactions with Tat. Collectively, the results show that opioid-HIV interactions in hippocampal area CA1 are more nuanced than previously assumed, and appear to vary depending on the outcome assessed and on the pharmacokinetics of morphine exposure.

Differences in cue-induced brain activation between long-term methadone maintenance treatment and protracted abstinence in heroin use disorder patients: a functional magnetic resonance imaging study

Background

Heroin use disorder (HUD) remains one of the gravest public health issues in China. Methadone maintenance treatment (MMT) and protracted abstinence (PA) are the most commonly used treatments for HUD. Although both treatment approaches can alleviate heroin cravings, a previous study found that MMT patients had stronger cue-induced brain activation than patients undergoing PA; however, the changes associated with long-term treatment are unclear.

Methods

Male patients with HUD who had been undergoing either PA (n=24) or MTT (n=21) for approximately 12 months, together with 20 demographically matched healthy controls, completed an event-related functional magnetic resonance imaging (fMRI) task. The subjective craving for heroin was evaluated using a visual analog scale.

Results

Compared to the healthy controls, the MMT and PA groups demonstrated significantly higher brain activation in the left pallidum, middle occipital gyrus, postcentral gyrus, anterior cingulate cortex, middle cingulate cortex, inferior parietal lobule, superior parietal lobule, amygdala, hippocampus, right inferior temporal gyrus, inferior frontal gyrus triangularis, and caudate during exposure to heroin-related cues. Compared to those undergoing PA, patients in the MMT group demonstrated significantly higher brain activation in all of these regions. Except for the left inferior parietal lobule and left superior parietal lobule, there were no statistically significant differences between the PA and healthy control groups. The MMT patients showed significantly higher subjective cravings before and after exposure to heroin cues than the PA group, but there was no significant difference in the change in subjective cravings between the 2 groups.

Conclusions

The results suggested that although the HUD patients receiving long-term MMT complied with the treatment, they still had higher subjective cravings and cue-induced brain activation than those undergoing PA. Therefore, long-term PA appears to be more beneficial than MMT in reducing the salience value of drug cues in patients with HUD.

Suicide Risk and Addiction: The Impact of Alcohol and Opioid Use Disorders

Purpose of Review

Suicide is a major public health concern and a leading cause of death in the US. Alcohol and opioid use disorders (AUD/OUD) significantly increase risk for suicidal ideation, attempts, and death, and are the two most frequently implicated substances in suicide risk. We provide a brief overview of shared risk factors and pathways in the pathogenesis of AUD/OUD and suicidal thoughts and behaviors. We also review clinical recommendations on inpatient care, pharmacotherapy, and psychotherapeutic interventions for people with AUD/OUD and co-occurring suicidal ideation and behavior.

Recent Findings

Among people with an underlying vulnerability to risk-taking and impulsive behaviors, chronic alcohol intoxication can increase maladaptive coping behaviors and hinder self-regulation, thereby increasing the risk of suicide. Additionally, chronic opioid use can result in neurobiological changes that lead to increases in negative affective states, jointly contributing to suicide risk and continued opioid use. Despite significantly elevated suicide risk in individuals with AUD/OUD, there is a dearth of research on pharmacological and psychosocial interventions for co-occurring AUD/OUD and suicidal ideation and behavior.

Summary

Further research is needed to understand the effects of alcohol and opioid use on suicide risk, as well as address notable gaps in the literature on psychosocial and pharmacological interventions to lower risk for suicide among individuals with AUD/OUD.

Neonatal opioid exposure: public health crisis and novel neuroinflammatory disease

Substance use, specifically the use of prescription and non-prescription opioids among pregnant women, is a major public health issue and chief contributor to the opioid crisis. The prevalence of Neonatal Opioid Withdrawal Syndrome has risen 5-fold in the past decade, and is a well-recognized consequence of perinatal opioid exposure. By contrast, the long-term damage to the developing brain from opioid medications is just beginning to be recognized as a serious concern. Published data suggest that opioid exposure commencing in utero negatively affects the maturation of the neural-immune system, and trajectory of central nervous system development. Methadone induces peripheral immune hyper-reactivity, lasting structural and microstructural brain injury, and significant deficits in executive function and cognitive control in adult animals following in utero exposure. Thus, to address the cascading public health crisis stemming from the multitude of infants with in utero opioid exposure who will grow up with altered neurodevelopmental trajectories, rigorous preclinical, mechanistic studies are required. Such studies will define the long-term sequelae of prenatal opioid exposure in an effort to develop appropriate and targeted interventions. Specifically, the development of novel fluid, neuroimaging and biobehavioral biomarkers will be the most useful to aid in early identification and treatment of opioid exposed infants with the greatest risk of poor clinical outcomes. These studies will be essential to understand how in utero insults determine brain structure and function in adulthood, and what targeted interventions will be required to improve long-term outcomes in the countless children being born exposed to opioids each year.

Neuroimaging in infants with prenatal opioid exposure: Current evidence, recent developments and targets for future research

Prenatal opioid exposure (POE) has shown to be a risk factor for adverse long-term cognitive and behavioral outcomes in offspring. However, the neural mechanisms of these outcomes remain poorly understood. While preclinical and human studies suggest that these outcomes may be due to opioid-mediated changes in the fetal and early postnatal brain, other maternal, social, and environmental factors are also shown to play a role. Recent neuroimaging studies reveal brain alterations in children with POE. Early neuroimaging and novel methodology could provide an in vivo mechanistic understanding of opioid mediated alterations in developing brain. However, this is an area of ongoing research. In this review we explore recent imaging developments in POE, with emphasis on the neonatal and infant brain, and highlight some of the challenges of imaging the developing brain in this population. We also highlight evidence from animal models and imaging in older children and youth to understand areas where future research may be targeted in infants with POE.

Functional connectivity of posterior cingulate gyrus in heroin dependents treated by methadone maintenance and protracted abstinence measures: an event-related fMRI study

Protracted abstinence (PA) and Methadone maintenance treatment (MMT) are two main types of heroin addiction treatment, however, the effects of both measures on the functional connectivity (FC) of the brain in heroin dependents in the drug cue event-related response are unclear. Functional magnetic resonance imaging (fMRI) based drug cue-reactivity task has been widely used in addiction research, which may provide a new way to understand the change of brain function during a certain period of treatment. The default function network (DMN) with posterior cingulate cortex (PCC) as the core is generally involved in the process of addiction. The aim of the present study was to explore the brain response of FC in patients with heroin-dependent during PA, MMT treatment under task-fMRI. Twenty-two heroin-dependent patients during PA, 18 heroin-dependent patients during MMT and 16 healthy control (HC) individuals were included to conduct the heroin cue-reactivity task during fMRI. The MMT and PA patients' subjective craving for heroin was evaluated. The psychophysiological interaction (PPI) analysis of SPM12 was used to get FC during the task state. There was a significant difference on FC between PCC and the right medial Prefrontal Cortex (mPFC) in three groups. The post-hoc analysis showed that there was a significant difference of brain regions between the MMT and the PA group. The FC of PCC-mPFC in the MMT group was significantly stronger than that in the PA group. Compared with the PA group, the FC of the DMN in the MMT group was significantly increased under drug cue response. Therefore, PA is more beneficial for the heroin-dependent patients to lower the salience value of drug related cues, in turn to reduce relapse risks. It also reflected the important role of PCC-mPFC pathway in heroin dependents induced by heroin cues.

Increased Pain Symptomatology Among Females vs. Males With Fragile X-Associated Tremor/Ataxia Syndrome

Individuals with the fragile X premutation report symptoms of chronic pain from multiple systems, have increased incidence of comorbid conditions where pain is a prominent feature, and pathophysiology that supports disrupted pain regulation, inflammation, and energy imbalance. Less is known about how pain manifests for the subpopulation of carriers that develop the motor and cognitive changes of fragile X-associated tremor and ataxia syndrome (FXTAS), and how pain may differ between men and women. We gathered data collected from 104 males and females with FXTAS related to chronic pain, comorbid conditions related to pain, and medications used for pain control to further explore the types of pain experienced and to better characterize how individuals with the fragile X premutation experience pain sensation across genders. We found that women experience significantly more pain symptoms than men, particularly allodynia (20 vs. 2.0%, p = 0.008), peripheral neuropathy pain (43.9 vs. 25.4%, p = 0.0488), migraine (43.9 vs. 14.5%, p = 0.0008), fibromyalgia (26.8 vs. 0%, p = 0.0071) and back pain (48.5 vs. 23.4%, p = 0.008). We found onset of peripheral neuropathy predicts the onset of ataxia (β = 0.63 ± 0.25, p = 0.019) and tremor (β = 0.56 ± 0.17, p = 0.004) across gender. Women also report significantly more anxiety (82.9 vs. 39.7%, p < 0.001), which has implications for ideal pain treatment. These pain symptoms need to be recognized in the medical history and treated appropriately, with consideration for overlapping comorbidities.

The molecular neurobiology and neuropathology of opioid use disorder

The number of people diagnosed with opioid use disorder has skyrocketed as a consequence of the opioid epidemic and the increased prescribing of opioid drugs for chronic pain relief. Opioid use disorder is characterized by loss of control of drug taking, continued drug use in the presence of adverse consequences, and repeated relapses to drug taking even after long periods of abstinence. Patients who suffer from opioid use disorder often present with cognitive deficits that are potentially secondary to structural brain abnormalities that vary according to the chemical composition of the abused opioid. This review details the neurobiological effects of oxycodone, morphine, heroin, methadone, and fentanyl on brain neurocircuitries by presenting the acute and chronic effects of these drugs on the human brain. In addition, we review results of neuroimaging in opioid use disorder patients and/or histological studies from brains of patients who had expired after acute intoxication following long-term use of these drugs. Moreover, we include relevant discussions of the neurobiological mechanisms involved in promoting abnormalities in the brains of opioid-exposed patients. Finally, we discuss how novel strategies could be used to provide pharmacological treatment against opioid use disorder.

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Brain abnormalities caused by opioid intoxication.

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Intoxication of opioids leads to defects in brain neurocircuitries.

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Insight into the molecular mechanisms associated with craving in heroin addicts.

Opioid and neuroHIV Comorbidity - Current and Future Perspectives

With the current national opioid crisis, it is critical to examine the mechanisms underlying pathophysiologic interactions between human immunodeficiency virus (HIV) and opioids in the central nervous system (CNS). Recent advances in experimental models, methodology, and our understanding of disease processes at the molecular and cellular levels reveal opioid-HIV interactions with increasing clarity. However, despite the substantial new insight, the unique impact of opioids on the severity, progression, and prognosis of neuroHIV and HIV-associated neurocognitive disorders (HAND) are not fully understood. In this review, we explore, in detail, what is currently known about mechanisms underlying opioid interactions with HIV, with emphasis on individual HIV-1-expressed gene products at the molecular, cellular and systems levels. Furthermore, we review preclinical and clinical studies with a focus on key considerations when addressing questions of whether opioid-HIV interactive pathogenesis results in unique structural or functional deficits not seen with either disease alone. These considerations include, understanding the combined consequences of HIV-1 genetic variants, host variants, and μ-opioid receptor (MOR) and HIV chemokine co-receptor interactions on the comorbidity. Lastly, we present topics that need to be considered in the future to better understand the unique contributions of opioids to the pathophysiology of neuroHIV. Graphical Abstract Blood-brain barrier and the neurovascular unit. With HIV and opiate co-exposure (represented below the dotted line), there is breakdown of tight junction proteins and increased leakage of paracellular compounds into the brain. Despite this, opiate exposure selectively increases the expression of some efflux transporters, thereby restricting brain penetration of specific drugs.

Suppressor capacity of copper nanoparticles biosynthesized using Crocus sativus L. leaf aqueous extract on methadone-induced cell death in adrenal phaeochromocytoma (PC12) cell line

In this research, we prepared and formulated a neuroprotective supplement (copper nanoparticles in aqueous medium utilizing Crocus sativus L. Leaf aqueous extract) for determining its potential against methadone-induced cell death in PC12. The results of chemical characterization tests i.e., FE-SEM, FT-IR, XRD, EDX, TEM, and UV–Vis spectroscopy revealed that the study showed that copper nanoparticles were synthesized in the perfect way possible. In the TEM and FE-SEM images, the copper nanoparticles were in the mean size of 27.5 nm with the spherical shape. In the biological part of the present research, the Rat inflammatory cytokine assay kit was used to measure the concentrations of inflammatory cytokines. Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) test was used to show DNA fragmentation and apoptosis. Caspase-3 activity was assessed by the caspase activity colorimetric assay kit and mitochondrial membrane potential was studied by Rhodamine123 fluorescence dye. Also, the cell viability of PC12 was measured by trypan blue assay. Copper nanoparticles-treated cell cutlers significantly (p ≤ 0.01) decreased the inflammatory cytokines concentrations, caspase-3 activity, and DNA fragmentation and they raised the cell viability and mitochondrial membrane potential in the high concentration of methadone-treated PC12 cells. The best result of neuroprotective properties was seen in the high dose of copper nanoparticles i.e., 4 µg. According to the above results, copper nanoparticles containing C. sativus leaf aqueous extract can be used in peripheral nervous system treatment as a neuroprotective promoter and central nervous system after approving in the clinical trial studies in humans.

Methadone-induced encephalopathy: a case series and literature review

BACKGROUND

Accidental ingestion or consumption of supra-therapeutic doses of methadone can result in neurological sequelae in humans. We aimed to determine the neurological deficits of methadone-poisoned patients admitted to a referral poisoning hospital using brain magnetic resonance (MR) and diffusion weighted (DW) imaging.

METHODS

In this retrospective study, brain MRIs of the patients admitted to our referral center due to methadone intoxication were reviewed. Methadone intoxication was confirmed based on history, congruent clinical presentation, and confirmatory urine analysis. Each patient had an MRI with Echo planar T1, T2, FLAIR, and DWI and apparent deficient coefficient (ADC) sequences without contrast media. Abnormalities were recorded and categorized based on their anatomic location and sequence.

RESULTS

Ten patients with abnormal MRI findings were identified. Eight had acute- and two had delayed-onset encephalopathy. Imaging findings included bilateral confluent or patchy T2 and FLAIR high signal intensity in cerebral white matter, cerebellar involvement, and bilateral occipito-parietal cortex diffusion restriction in DWI. Internal capsule involvement was identified in two patients while abnormality in globus pallidus and head of caudate nuclei were reported in another. Bilateral cerebral symmetrical confluent white matter signal abnormality with sparing of subcortical U-fibers on T2 and FLAIR sequences were observed in both patients with delayed-onset encephalopathy.

CONCLUSIONS

Acute- and delayed-onset encephalopathies are two rare adverse events detected in methadone-intoxicated patients. Brain MRI findings can be helpful in detection of methadone-induced encephalopathy.

[Aging in a methadone maintenance program. A perspective from the framework of social determinants of health]

OBJECTIVE

People on methadone treatment have increased their life expectancy, aging prematurely with comorbidities. The objective of this study was to know the sociodemographic and clinical profile of these people in the Center for Addiction Care in the district of Latina (belonging to Madrid Salud), as well as the perception of the influence of the treatment on their aging. The Social Determinants of Health Model was used as a framework.

METHODS

A mixed methodology was used in two phases: a quantitative one, to describe the sociodemographic and clinical characteristics of the study population; and another qualitative one, through semi-structured interviews to an intentional sample, to explore the history of life and the perception of future needs regarding the health of the participants.

RESULTS

The results highlighted that the average age of the sample was 48.28 years, that they were mostly men (81.25%), of Spanish origin, with a low level of education and economics and with a medium stay in treatment with methadone of ± 13 years. An increase in mental pathologies was found the more years they had been in the program, as well as, at a lower age of onset in consumption, the presence of HIV and Hepatitis C virus increased. In their speeches it was found that the social determinants of Health have conditioned its vital history.

CONCLUSIONS

Both consumption and methadone contribute to its stigmatization, not favoring its normalized inclusion in society and determining a high state of vulnerability. This increases as age does, not receive adequate resources to meet their future needs.

Peripheral levels of BDNF and opiate-use disorder: literature review and update

Several neurobiological factors are related to opiate-use disorder (OUD), and among them, neurotrophins have a relevant role. Brain-derived neurotrophic factor (BDNF) is a central neurotrophin involved in many neuronal processes, and it has been related to several psychiatric diseases and addictive disorders. BDNF can be measured in plasma and serum; its levels may reflect BDNF concentrations in the central nervous system (CNS) and, indirectly, CNS processes. Hence, peripheral BDNF could be a biomarker in clinical practice. This manuscript explores the findings about peripheral BDNF and OUD in humans. Opiates induce neurotoxicity in the CNS, which may be correlated with modifications in BDNF expression. Thus, basal levels of peripheral BDNF in OUD patients may be altered, which could be modified with abstinence. Also, opiates may modify epigenetic processes that may be associated with peripheral concentrations of BDNF, and in this line, withdrawal could reflect recovering processes in the CNS. Additionally, treatment modifies the peripheral concentrations of BDNF, but the clinical implications of those changes are yet not elucidated. No specific conclusion can be performed and more investigation in this area is necessary to elucidate the real potential of peripheral BDNF as a biomarker.

Opiate Drugs with Abuse Liability Hijack the Endogenous Opioid System to Disrupt Neuronal and Glial Maturation in the Central Nervous System

The endogenous opioid system, comprised of multiple opioid neuropeptide and receptor gene families, is highly expressed by developing neural cells and can significantly influence neuronal and glial maturation. In many central nervous system (CNS) regions, the expression of opioid peptides and receptors occurs only transiently during development, effectively disappearing with subsequent maturation only to reemerge under pathologic conditions, such as with inflammation or injury. Opiate drugs with abuse liability act to modify growth and development by mimicking the actions of endogenous opioids. Although typically mediated by μ-opioid receptors, opiate drugs can also act through δ- and κ-opioid receptors to modulate growth in a cell-type, region-specific, and developmentally regulated manner. Opioids act as biological response modifiers and their actions are highly contextual, plastic, modifiable, and influenced by other physiological processes or pathophysiological conditions, such as neuro-acquired immunodeficiency syndrome. To date, most studies have considered the acute effects of opiates on cellular maturation. For example, activating opioid receptors typically results in acute growth inhibition in both neurons and glia. However, with sustained opioid exposure, compensatory factors become operative, a concept that has been largely overlooked during CNS maturation. Accordingly, this article surveys prior studies on the effects of opiates on CNS maturation, and also suggests new directions for future research in this area. Identifying the cellular and molecular mechanisms underlying the adaptive responses to chronic opiate exposure (e.g., tolerance) during maturation is crucial toward understanding the consequences of perinatal opiate exposure on the CNS.