34 research outputs found
comparison of methadone and levomethadone in long-term treatment
Background This study aimed to investigate the development of opioid tolerance
in patients receiving long-term methadone maintenance treatment (MMT). Methods
A region-wide cross-sectional study was performed focusing on dosage and
duration of treatment. Differences between racemic methadone and levomethadone
were examined. All 20 psychiatric hospitals and all 110 outpatient clinics in
Berlin licensed to offer MMT were approached in order to reach patients under
MMT fulfilling the DSM IV criteria of opiate dependence. In the study, 720
patients treated with racemic methadone or levomethadone gave information on
the dosage of treatment. Out of these, 679 patients indicated the duration of
MMT. Results Treatment with racemic methadone was reported for 370 patients
(54.5 %), with levomethadone for 309 patients (45.5 %). Mean duration of MMT
was 7.5 years. We found a significant correlation between dosage and duration
of treatment, both in a conjoint analysis for the two substances racemic
methadone and levomethadone and for each substance separately. These effects
remained significant when only patients receiving MMT for 1 year or longer
were considered, indicating proceeding tolerance development in long-term
treatment. When correlations were compared between racemic methadone and
levomethadone, no significant difference was found. Conclusions Our data show
a tolerance development under long-term treatment with both racemic methadone
and levomethadone. Tolerance development did not differ significantly between
the two substances
Alcohol use disorder is associated with DNA methylation-based shortening of telomere length and regulated by TESPA1:implications for aging
Chronic heavy alcohol consumption is associated with increased mortality and morbidity and often leads to premature aging; however, the mechanisms of alcohol-associated cellular aging are not well understood. In this study, we used DNA methylation derived telomere length (DNAmTL) as a novel approach to investigate the role of alcohol use on the aging process. DNAmTL was estimated by 140 cytosine phosphate guanines (CpG) sites in 372 individuals with alcohol use disorder (AUD) and 243 healthy controls (HC) and assessed using various endophenotypes and clinical biomarkers. Validation in an independent sample of DNAmTL on alcohol consumption was performed (N = 4219). Exploratory genome-wide association studies (GWAS) on DNAmTL were also performed to identify genetic variants contributing to DNAmTL shortening. Top GWAS findings were analyzed using in-silico expression quantitative trait loci analyses and related to structural MRI hippocampus volumes of individuals with AUD. DNAmTL was 0.11-kilobases shorter per year in AUD compared to HC after adjustment for age, sex, race, and blood cell composition (p = 4.0 × 10(−12)). This association was partially attenuated but remained significant after additionally adjusting for BMI, and smoking status (0.06 kilobases shorter per year, p = 0.002). DNAmTL shortening was strongly associated with chronic heavy alcohol use (ps < 0.001), elevated gamma-glutamyl transferase (GGT), and aspartate aminotransferase (AST) (ps < 0.004). Comparison of DNAmTL with PCR-based methods of assessing TL revealed positive correlations (R = 0.3, p = 2.2 × 10(−5)), highlighting the accuracy of DNAmTL as a biomarker. The GWAS meta-analysis identified a single nucleotide polymorphism (SNP), rs4374022 and 18 imputed ones in Thymocyte Expressed, Positive Selection Associated 1(TESPA1), at the genome-wide level (p = 3.75 × 10(−8)). The allele C of rs4374022 was associated with DNAmTL shortening, lower hippocampus volume (p < 0.01), and decreased mRNA expression in hippocampus tissue (p = 0.04). Our study demonstrates DNAmTL-related aging acceleration in AUD and suggests a functional role for TESPA1 in regulating DNAmTL length, possibly via the immune system with subsequent biological effects on brain regions negatively affected by alcohol and implicated in aging
Acute alcohol effects on explicit and implicit motivation to drink alcohol in socially drinking adolescents
Alcohol-related cues can evoke explicit and implicit motivation to drink alcohol. Concerning the links between explicit and implicit motivation, there are mixed findings. Therefore, we investigated both concepts in 51 healthy 18- to 19-year-old males, who are less affected by neuropsychological deficits in decision-making that are attributed to previous alcohol exposure than older participants. In a randomized crossover design, adolescents were infused with either alcohol or placebo. Self-ratings of alcohol desire, thirst, well-being and alcohol effects comprised our explicit measures of motivation. To measure implicit motivation, we used money and drink stimuli in a Pavlovian conditioning (Pc) task and an Approach-Avoidance Task (AAT). Alcohol administration increased explicit motivation to drink alcohol, reduced Pc choices of alcoholic drink-conditioned stimuli, but had no effect on the AAT. This combination of results might be explained by differences between goal-directed and habitual behavior or a temporary reduction in rewarding outcome expectancies. Further, there was no association between our measures of motivation to drink alcohol, indicating that both self-reported motivation to drink and implicit approach tendencies may independently contribute to adolescents’ actual alcohol intake. Correlations between Alcohol Use Disorders Identification Test (AUDIT) scores and our measures of motivation to drink alcohol suggest that interventions should target high-risk adolescents after alcohol intake
Automatic approach bias towards smoking cues is present in smokers but not in ex-smokers.
RATIONALE: Drug-addicted individuals show automatic approach tendencies towards drug-related cues, i.e., an approach bias (ApB). Nevertheless, little is known about ApB in tobacco smokers and about the presence of ApB after smoking abstinence. OBJECTIVES: We investigated ApB to smoking cues in heavy tobacco smokers versus never-smokers and studied its relation to smoking characteristics and craving. Second, we compared ApBs of heavy smokers with biases of abstinent heavy smokers. METHOD: A group of current heavy smokers (n = 24), ex-smokers who were abstinent for at least 5 years (n = 20), and never-smokers (n = 20) took part in the experiment. An indirect smoking approach avoidance task was performed, in which participants were required to respond to pictures of smoking and neutral cues by pulling (approach) or pushing (avoid) on a joystick, according to the content-irrelevant format of the picture (landscape or portrait). Craving scores were examined using the Questionnaire of Smoking Urges. RESULTS: Heavy smokers showed an ApB for smoking cues compared to ex-smokers and never-smokers, which correlated positively to craving scores. There were no group differences in ApB scores for ex-smokers and never-smokers. CONCLUSION: These results suggest that ApBs for smoking cues are present in heavy smokers and decrease after long-term successful smoking cessation
An experimental test of integrating imagery with approach bias modification for alcohol: A cautionary tale
In terms of dual process models, behaviour can be conceived of as the outcome of an interplay between reflective, top-down and impulsive, bottom-up processes. Behaviour change interventions may benefit from targeting both types of processes in a coherent way. One approach to this, in the context of reducing hazardous drinking, is to combine imagery involving real-life situations involving alcohol with the simple actions involved in Approach Bias Modification (ApBM), a form of Cognitive Bias Modification. We developed and tested a version of this Imagery-enhanced Approach Bias Modification (IApBM) in an experimental design, with two independent factors: imagery versus control and ApBM versus control training components (N = 139). An effect of integrating the training factors was hypothesized on the alcohol-approach bias of an alcohol Approach-Avoidance Task. Further exploratory analyses were performed for the bias on alcohol-related Single Attribute Implicit Association Tests and on alcohol-related questionnaires. Finally, the psychometric properties of an imagery interference effect during training were explored. Results showed no benefit of the training and in fact suggested a negative interaction in which combining the training components appeared to block reductions in craving effected by each in isolation. The reliability of the imagery-related interference effect was high and the effect was correlated with alcohol-related scales. In conclusion, it appears that interference between training components decreases their individual effects when combining imagery and ApBM in the current way. The imagery-related interference effects that could be measured during training conditions may be useful as an implicit measure of automatic processes underlying hazardous drinking. [Abstract copyright: © 2022 British Psychological Society.
Neural correlates of changing food choices while bypassing values
Current theories suggest that altering choices requires value modification. To investigate this, normal-weight female participants’ food choices and values were tested before and after an approach-avoidance training (AAT), while neural activity was recorded during the choice task using functional magnetic resonance imaging (fMRI). During AAT, participants consistently approached low- while avoiding high-calorie food cues. AAT facilitated low-calorie food choices, leaving food values unchanged. Instead, we observed a shift in indifference points, indicating the decreased contribution of food values in food choices. Training-induced choice shifts were associated with increased activity in the posterior cingulate cortex (PCC). In contrast, the medial PFC activity was not changed. Additionally, PCC gray matter density predicted individual differences in training-induced functional changes, suggesting anatomic predispositions to training impact. Our findings demonstrate neural mechanisms underlying choice modulation independent of valuation-related processes, which has substantial theoretical significance for decision-making frameworks and translational implications for health-related decisions resilient to value shifts
Collateral Damage: Neurological Correlates of Non-Fatal Overdose in the Era of Fentanyl-Xylazine
Non-fatal opioid overdoses are associated with significant morbidity. Hypoxic brain injury caused by opioid-induced respiratory depression is a key mechanism of such morbidity. For example, reports describe an amnestic syndrome in opioid users associated with acute injury to the hippocampus, a brain region that is highly susceptible to hypoxic injury. In our recent study we investigated the effects of non-fatal opioid overdose on the hippocampal volume in a well-characterized sample of opioid use disorder (OUD) patients with a history of overdose (OD) compared to those with no prior overdose (NOD). Using structural magnetic resonance imaging (MRI) and voxel-based morphometry, we observed lower hippocampal volume in patients with a history OD than in the NOD group. These findings support an association between non-fatal opioid overdose and hippocampal injury, which we hypothesize contributes to recently reported cases of OUD related amnestic syndrome. Here we review our study findings and the potential pathophysiological mechanisms underlying the acute and delayed hippocampal injury in nonfatal opioid overdose. We also discuss the implications for the risk of overdose and brain injury with the increased prevalence of fentanyl and xylazine contamination of the illicit opioid supply. Lastly, we highlight considerations for clinical management of the underappreciated neurological injury and cognitive dysfunction in OUD patients
Food addiction: a common neurobiological mechanism with drug abuse.
Drugs and food both exert a rewarding effect through the firing of dopamine neurons in the ventral tegmental area, resulting in the release of dopamine into the nucleus accumbens and effects on the mesolimbic pathway. Here, we review the neuroimaging literature to consider the validity of food addiction and the common neurobiological mechanisms that overlap in food and drug addiction. This review paper focuses on findings from Positron Emission Tomography (PET), functional Magnetic Resonance Imaging (fMRI) and structural imaging studies, as well as evidence from neuroimaging studies of bariatric surgery and pharmacological interventions on obese individuals. We examine not only functional and structural changes in the mesolimbic pathways, but also in other frontal areas shown to be involved in drug addiction, including the prefrontal cortex, orbitofrontal cortex and anterior cingulate cortex, as well as changes in neurotransmitter systems beyond dopaminergic systems