Addiction Biology

Alcohol use disorder (AUD) has been associated with attentional deficits and impairments of working memory. Meanwhile, attention and working memory are critical for time perception. However, it remains unclear how time perception alters in AUD patients and how attention and working memory affect their time perception. The current study aims to clarify the time perception characteristics of AUD patients and the cognitive mechanisms underlying their time perception dysfunction. Thirty-one patients (three of them were excluded) with AUD and thirty-one matched controls completed the Time Bisection Task, Attention Network Test and Digital Span Backward Test to assess their abilities in time perception, attention network and working memory, respectively...

Despite synthetic cannabinoids' (SCs) prevalent use among humans, these substances often lack comprehensive pharmacological data, primarily due to their rapid emergence in the market. This study aimed to discern differences and causal factors among four SCs (ADB-BICA, ADB-BINACA, ADB-4en-PINACA and MDMB-4en-PINACA), with respect to locomotor activity, body temperature and nociception threshold. Adult male C57BL/6 mice received intraperitoneal injections of varying doses (0.5, 0.1 and 0.02 mg/kg) of these compounds...

Alcohol use disorder (AUD) is characterized by cycles of abuse, withdrawal, and relapse. Neuroadaptations in the basal ganglia are observed in AUD; specifically in the putamen, globus pallidus (GP), and ventral pallidum (VP). These regions are associated with habit formation, drug-seeking behaviors, and reward processing. While previous studies have shown the crucial role of glial cells in drug seeking, it remains unknown whether glial cells in the basal ganglia are altered in AUD. Glial cells in the putamen, GP, and VP were examined in human post-mortem tissue of AUD and alcohol remission cases...

The lymphocyte-related ratios, neutrophil-to-lymphocyte ratio (NLR), monocyte-to-lymphocyte ratio (MLR) and platelet-to-lymphocyte ratio (PLR) are new measures of inflammation within the body. Few studies have investigated the inflammatory response of patients with methamphetamine-induced psychotic disorder. Clinically, the psychotic symptoms and behavioural manifestation of methamphetamine-induced psychotic disorder are often indistinguishable from paranoid schizophrenia. We aimed to determine the differences in these inflammatory markers between patients with methamphetamine-induced psychotic disorder, patients with schizophrenia and healthy individuals...

Neural measures of alcohol cue incentive salience have been associated with retrospective reports of riskier alcohol use behaviour and subjective response profiles. This study tested whether the P3 event-related potential (ERP) elicited by alcohol-related cues (ACR-P3) can forecast alcohol use and craving during real-world drinking episodes. Participants (N = 262; Mage  = 19.53; 56% female) completed a laboratory task in which they viewed images of everyday objects (Neutral), non-alcohol drinks (NonAlc) and alcohol beverages (Alc) while EEG was recorded and then completed a 21-day ecological momentary assessment (EMA) protocol in which they recorded alcohol craving and consumption...

Adolescent alcohol use is a strong predictor for the subsequent development of alcohol use disorders later in life. Additionally, adolescence is a critical period for the onset of affective disorders, which can contribute to problematic drinking behaviours and relapse, particularly in females. Previous studies from our laboratory have shown that exposure to adolescent intermittent ethanol (AIE) vapour alters glutamatergic transmission in the bed nucleus of the stria terminalis (BNST) and, when combined with adult stress, elicits sex-specific changes in glutamatergic plasticity and negative affect-like behaviours in mice...

Here, we present recent studies suggesting that specific DRD3 single nucleotide polymorphisms (SNPs, e.g. rs324029 and rs2654754) might serve as prognostic biomarkers for opioid use disorder (OUD). Additionally, preclinical studies with novel dopamine 3 receptor (D3R) partial agonists and antagonists have been evaluated as candidate OUD therapeutics and have shown a reduced risk of cardiovascular toxicity compared with the original D3R antagonist. From these findings, we argue that DRD3 SNPs could serve as a diagnostic tool for assessing OUD risk and that more research is warranted examining the D3R as a safe and effective therapeutic target for treating OUD...

Sensation seeking is bidirectionally associated with levels of alcohol consumption in both adult and adolescent samples, and shared neurobiological and genetic influences may in part explain these associations. Links between sensation seeking and alcohol use disorder (AUD) may primarily manifest via increased alcohol consumption rather than through direct effects on increasing problems and consequences. Here the overlap among sensation seeking, alcohol consumption, and AUD was examined using multivariate modelling approaches for genome-wide association study (GWAS) summary statistics in conjunction with neurobiologically informed analyses at multiple levels of investigation...

Stimulant betel quid (SBQ) containing Piper betle leaf (L), green unripe Areca catechu nut (AN) and the alkalizing agent, slaked lime, is an addictive, carcinogenic stimulant, with no pharmacotherapy, chewed by millions of people in the Asia/Pacific region. We compared the in vivo physiological profile of chewing (1) non-stimulant P. betle leaf+AN (LAN), (2) SBQ utilizing slaked lime and (3) a novel SBQ utilizing Mg(OH)2 , as an alkalizing agent, by measuring physiological parameters of intoxication and these were correlated with in vitro levels of alkaloids measured by UHPLC-MS/MS...

Tobacco smoking is a serious health problem in society. While smoking rates are declining, smoking remains a serious risk to national health. Currently, there are several medications available to aid in smoking cessation. However, these medications have the disadvantages of low success rates in smoking cessation and various side effects. Therefore, natural-based smoking cessation aids are being suggested as a good alternative due to their accessibility and minimal side effects. The roots and stems of Acanthopanax koreanum (AK) Nakai, a plant that is native to Jeju Island, South Korea, have traditionally been used as tonic and sedatives...

Cocaine use disorder (CUD) is a worldwide public health condition that is suggested to induce pathological changes in macrostructure and microstructure. Repetitive transcranial magnetic stimulation (rTMS) has gained attention as a potential treatment for CUD symptoms. Here, we sought to elucidate whether rTMS induces changes in white matter (WM) microstructure in frontostriatal circuits after 2 weeks of therapy in patients with CUD and to test whether baseline WM microstructure of the same circuits affects clinical improvement...

N-Isopropylbenzylamine (N-ipb), a chain isomer of methamphetamine (METH) with similar physical properties, has been used as a substitute for METH in seized drug samples. However, the abuse potential of N-ipb remains unclear. Therefore, this study aimed to evaluate the abuse potential of N-ipb in comparison to METH, by using conditioned place preference (CPP), locomotor sensitization and intravenous self-administration tests. The results showed that N-ipb at a dose of 3 mg·kg-1 significantly induced CPP in mice, which was comparable to the effect of METH at 1 mg·kg-1 ...

Alcohol use disorder (AUD) is heritable. Thus, young adults with positive family histories represent an at-risk group relative to those without a family history, and if studied at a time when both groups have similar levels of alcohol use, it provides an opportunity to identify neural processing patterns associated with risk for AUD. Previous studies have shown that diminished response to potential reward is associated with genetic risk for AUD, but it is unclear how threat may modulate this response. We used a modified Monetary Incentive Delay task during fMRI to examine neural correlates of the interaction between threat and reward anticipation in a sample of young adults with (n = 31) and without (n = 44) family histories of harmful alcohol use...

Humans demonstrate significant behavioural advantages with particular perceptual dimensions (such as colour or shape) and when the relevant dimension is repeated in consecutive trials. These dimension-related behavioural modulations are significantly altered in neuropsychological and addiction disorders; however, their underlying mechanisms remain unclear. Here, we studied whether these behavioural modulations exist in other trichromatic primate species and whether repeated exposure to opioids influences them...

People with methamphetamine use disorder (MUD) struggle to shift their behaviour from methamphetamine-orientated habits to goal-oriented choices. The model-based/model-free framework is well suited to understand this difficulty by unpacking the computational mechanisms that support experienced-based (model-free) and goal-directed (model-based) choices. We aimed to examine whether 1) participants with MUD differed from controls on behavioural proxies and/or computational mechanisms of model-based/model-free choices; 2) model-based/model-free decision-making correlated with MUD symptoms; and 3) model-based/model-free deficits improved over six weeks in the group with MUD...

Allelic variations in the A118G SNP of the OPRM1 gene change opioid signaling; however, evaluations of how allelic differences may influence opioid effects are lacking. This human laboratory paradigm examined whether the AA versus AG/GG genotypes determined opioid response profiles. Individuals with limited opioid exposure (N = 100) completed a five-day within-subject, double-blind, placebo-controlled, residential study. Participants were admitted (Day 1), received 4 mg hydromorphone (Day 2) and 0 mg, 2 mg and 8 mg hydromorphone in randomized order (Days 3-5) and completed self-reported visual analog scale (VAS) ratings and Likert scales, observed VAS, and physiological responses at baseline and for 6...

Driving is a critical everyday task necessitating the rapid and seamless integration of dynamic visually derived information to guide neurobehaviour. Biological markers are frequently employed to detect Δ9-tetrahydrocannabinol (THC) consumption among drivers during roadside tests, despite not necessarily indicating impairment. Characterising THC-specific alterations to oculomotor behaviour may offer a more sensitive measure for indexing drug-related impairment, necessitating discrimination between acute THC effects, chronic use and potential tolerance effects...

Addictions are thought to be fostered by the emergence of poorly regulated mesocorticolimbic responses to drug-related cues. The development and persistence of these responses might be promoted by altered glutamate transmission, including changes to type 5 metabotropic glutamate receptors (mGluR5s). Unknown, however, is when these changes arise and whether the mGluR5 and mesocorticolimbic alterations are related. To investigate, non-dependent cocaine polydrug users and cocaine-naïve healthy controls underwent a positron emission tomography scan (15 cocaine users and 14 healthy controls) with [11 C]ABP688, and a functional magnetic resonance imaging scan (15/group) while watching videos depicting activities with and without cocaine use...

There is a high frequency of comorbidity of alcohol use disorder (AUD) and depression in human populations. We have studied this relationship in our lab using the social defeat stress (SDS) model, which results in both depression-like behaviours and increased alcohol consumption in male mice. However, standard SDS procedures are difficult to use in female mice due to a lack of territorial aggression. In the experiments presented here, we used vicarious defeat stress (VDS) to assess social withdrawal and alcohol consumption in female C57BL6/J mice...

As a chewing hobby, areca nut (Areca catechu L.) has become the most common psychoactive substance in the world, besides tobacco, alcohol and caffeinated beverages. Moreover, as a first-class carcinogen designated by International Agency for Research on Cancer, long-term chewing areca nut can result in oral mucosal diseases and even oral cancer. To clarify the potential mechanism of areca nut addiction, an integrated strategy of metabolomics and network pharmacology was adopted in this study. Network pharmacology study indicated that all the key targets related to areca nut addiction could be regulated by arecoline and pointed out the importance of G-protein coupled receptor signalling pathway...