Acute D3 Antagonist GSK598809 Selectively Enhances Neural Response During Monetary Reward Anticipation in Drug and Alcohol Dependence.

Evidence suggests that disturbances in neurobiological mechanisms of reward and inhibitory control maintain addiction and provoke relapse during abstinence. Abnormalities within the dopamine system may contribute to these disturbances and pharmacologically targeting the D3 dopamine receptor (DRD3) is therefore of significant clinical interest. We used functional magnetic resonance imaging to investigate the acute effects of the DRD3 antagonist GSK598809 on anticipatory reward processing, using the monetary incentive delay task (MIDT), and response inhibition using the Go/No-Go task (GNGT). A double-blind, placebo-controlled, crossover design approach was used in abstinent alcohol dependent, abstinent poly-drug dependent and healthy control volunteers. For the MIDT, there was evidence of blunted ventral striatal response to reward in the poly-drug-dependent group under placebo. GSK598809 normalized ventral striatal reward response and enhanced response in the DRD3-rich regions of the ventral pallidum and substantia nigra. Exploratory investigations suggested that the effects of GSK598809 were mainly driven by those with primary dependence on alcohol but not on opiates. Taken together, these findings suggest that GSK598809 may remediate reward deficits in substance dependence. For the GNGT, enhanced response in the inferior frontal cortex of the poly-drug group was found. However, there were no effects of GSK598809 on the neural network underlying response inhibition nor were there any behavioral drug effects on response inhibition. GSK598809 modulated the neural network underlying reward anticipation but not response inhibition, suggesting that DRD3 antagonists may restore reward deficits in addiction.The research was carried out at the NIHR/Wellcome Trust Imperial Clinical Research Facility, the NIHR/Wellcome Trust Cambridge Research Facility and Clinical Trials Unit at Salford Royal NHS Foundation Trust, and is supported by the North West London, Eastern and Greater Manchester NIHR Clinical Research Networks

Factors affecting environmental management by small and micro firms: The importance of entrepreneurs’ attitudes and environmental investment

The paper investigates (1) the influence of external pressures, internal factors, and environmental attitudes of entrepreneurs on environmental proactive strategy in small and micro firms and (2) whether environmental proactive strategy impacts environmental investment and environmental performance. The study is based on a survey conducted in Italy and tests the set of hypotheses using a structural equations model. The results underline that external pressures and entrepreneurs’ attitudes are the most important predictors of environmental proactivity both for small and micro firms. The results also confirm a positive relationship between environmental proactivity and environmental investments as well as environmental performance. Yet, environmental investments show a strong influence on environmental performance. Commitment to environmental management by small and micro firms appears thus on the ground, showing that some substantive actions have started to be developed

The Stigma Scale: development of a standardised measure of the stigma of mental illness

Background There is concern about the stigma of mental illness, but it is difficult to measure stigma consistently. Aims To develop a standardised instrumentto measure the stigma of mental illness. Method We used qualitative data from interviews with mental health service users to develop a pilot scale with 42 items. We recruited 193 service users in order to standardise the scale. Of these, 93 were asked to complete the questionnaire twice, 2 weeks apart, of whom 60 (65%) did so. items with a test-retest reliability kappa coefficient of 0.4 or greater were retained and subjected to common factor analysis. Results The final 28-item stigma scale has a three-factor structure: the first concerns discrimination, the second disclosure and the third potential positive aspects of mental illness. Stigma scale scores were negatively correlated with global self-esteem. Conclusions This self-report questionnaire, which can be completed in 5-10 min, may help us understand more about the role of stigma of psychiatric illness in research and clinical settings. Declaration of interest None

Chronic alcohol exposure differentially modulates structural and functional properties of amygdala: A cross‐sectional study

Funder: GlaxoSmithKline; Id: http://dx.doi.org/10.13039/100004330Funder: Singapore National Research Foundation (NRF) FellowshipFunder: NUS YIAFunder: Medical Research Council Doctoral Training Program StudentshipAbstract: Animal models have shown that chronic alcohol exposure is associated with persistent neuroadaptations in amygdala synaptic function, whereas human studies have consistently reported amygdala grey‐matter volume (GMV) reductions in alcohol dependent patients (ADP). We hypothesised that chronic alcohol use associated with neuroadaptations may entail a reconfiguration of the amygdala's functional interactions and that these mechanisms may be affected by structural atrophy. We compared amygdala resting state functional connectivity (RSFC) using a whole brain seed‐based approach and amygdala GMV in abstinent ADP (n = 20) and healthy controls (HC; n = 39), balanced for age, gender and levels of head motion. The potential moderating influence of age, cumulative alcohol exposure, abstinence length and head motion was further examined in the two groups separately using correlational analyses. We found increased amygdala RSFC with substantia nigra/ventral tegmental area (SN/VTA) in ADP compared with HC. As expected, amygdala GMV was lower in ADP. Multiple regression analyses of the ADP group showed that amygdala‐SN/VTA RSFC increases were primarily associated with cumulative alcohol exposure rather than age, whereas amygdala GMV reductions were primarily associated with age rather than cumulative alcohol exposure. The same association between age and amygdala GMV was not observed amongst HC. Importantly, amygdala GMV and amygdala‐SN/VTA RSFC were uncorrelated in ADP, and neither measure was correlated with abstinence length. These results suggest that chronic alcohol exposure is associated with persistent elevations in amygdala‐SN/VTA RSFC and accelerated age‐related grey‐matter atrophy through potentially distinct mechanisms

Chronic alcohol exposure differentially modulates structural and functional properties of amygdala: A cross-sectional study

10.1111/adb.12980Addiction Biology264e1298

The Imperial College Cambridge Manchester (ICCAM) platform study: An experimental medicine platform for evaluating new drugs relapse prevention in addiction. Part A: Study description

Drug and alcohol dependence are global problems with substantial societal costs. There are few treatments for relapse prevention and therefore a pressing need for further study of brain mechanisms underpinning relapse circuitry. The Imperial College Cambridge Manchester (ICCAM) platform study is an experimental medicine approach to this problem: using functional magnetic resonance imaging (fMRI) techniques and selective pharmacological tools, it aims to explore the neuropharmacology of putative relapse pathways in cocaine, alcohol, opiate dependent, and healthy individuals to inform future drug development. Addiction studies typically involve small samples because of recruitment difficulties and attrition. We established the platform in three centres to assess the feasibility of a multisite approach to address these issues. Pharmacological modulation of reward, impulsivity and emotional reactivity were investigated in a monetary incentive delay task, an inhibitory control task, and an evocative images task, using selective antagonists for µ-opioid, dopamine D3 receptor (DRD3) and neurokinin 1 (NK1) receptors (naltrexone, GSK598809, vofopitant/aprepitant), in a placebo-controlled, randomised, crossover design. In two years, 609 scans were performed, with 155 individuals scanned at baseline. Attrition was low and the majority of individuals were sufficiently motivated to complete all five sessions (n=87). We describe herein the study design, main aims, recruitment numbers, sample characteristics, and explain the test hypotheses and anticipated study outputs