Events archive
See our past events, conferences and seminars.
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Recent past events
'Updates in Addiction Science: Symposium in celebration of the scholarship and practice of the late Dr Hugh Williams'
Wednesday 29th November 2023, 12pm to 5.30pm
University of Sussex Campus, Brighton and Sussex Medical School, Chowen Lecture Theatre, Falmer, BN1 9RY
A symposium open to public has been organised jointly by Brighton and Sussex Medical School (University of Sussex) and Sussex Partner NHS to present updates in addiction research and reflections on the contributions and scholarship of Dr Hugh Williams.
In this free afternoon event, insights on different addiction related topics will be given by researchers from the Brighton and Sussex Medical School, Sussex Addiction Research and Intervention Centre, King's College London and the organisation Change, Grow, Live (South East England).
For more information please check the event's agenda.
Neuronal Ensembles Regulating Opioid-Motivated Approach and Avoidance Behavior
Thursday 7th September, 13:00-14:00, University of Sussex Campus, Falmer (John Maynard Smith building - Room 4D13)
A special seminar has been organised by SARIC in collaboration with the University of Sussex' Centre of Excellence Sussex Neuroscience.
Dr Hermina Nedelscu is joining as our guest speaker from Scripps Research in San Diego to present her latest research study on addiction. Dr Nedelscu's research has focused on understanding the neurobiological basis of substance use disorders including mechanisms that lead to the development of dependence, attachment and withdrawal states, craving, relapse, and cognitive impairment.
Scripps Research is an influential research institution known for its impact on innovation in the field of biosciences applied to support and improve wellbeing.
The event is free and open to the public.
Sussex Addiction Research and Intervention Centre (SARIC) public panel
Sunday 23rd April 2023, 12:00 - 14:00, Brighton Centre, Brighton, BN1 2GR
Join us for a fascinating session which brings together learnings from the community and academia to better understand addiction.
The Sussex Addiction Research & Intervention Centre (SARIC) sponsored public session will focus on bridging the gap between academia and the community regarding the study, prevention, treatment, and harm reduction of addictions. Improving integrated and holistic care for addictions will be significant topics of discussion.
Panel members include Prof Hans Crombag (University of Sussex), Dr Pablo Romero Sanchiz (University of Sussex), Becky Marshall (Sussex Partnership NHS Foundation Trust), Clare Kennedy (Kennedy Street Recovery), James Murphy (Brighton & Hove's adolescent substance use and sexual health service, ru-ok?), and Ken Checinski (Change Grow Live).
Attendees must be aged 14+, and all people aged 16 and under must be accompanied by an adult.
Conferences
Drug and behavioural addictions: COVID-19 and beyond
Wednesday, July 7th, 2021
Through seminars and discussion, this symposium will explore the impact of COVID-19 on various forms of addiction and their treatment.
View the drug and behavioural addictions: Covid-19 and beyond symposium online.
There is an immediate need to pool an understanding of how the pandemic has impacted alcohol intake, drug use, and behavioural addictions. Collating this knowledge can help doctors and mental health professionals improve patient care by being aware of what’s happening during the pandemic and being prepared for potential mental health changes in their clients.
The Sussex Addiction Research and Intervention Centre (SARIC), which is hosting this knowledge exchange event, hopes to bring people together to (a) discuss how COVID-19 has impacted addiction-related mental health issues and (b) stimulate action to help prevent and treat potential addictions.
Session 1: Drug and alcohol use during COVID-19 (8:55–11:30, with breaks and discussion)
- Abhijit Nadkarni (London School of Hygiene & Tropical Medicine, UK): ‘I drink, therefore I am’: Stories from India.
- Fiona Walker (University of Sussex, UK): The effect of health messages on intentions to consume alcohol during the Covid-19 lockdown.
- Sarah Osborn and Nicholas Sinclair-House (University of Sussex, UK): COVID-19, alcohol and drugs: Trends and changes through lockdown and beyond.
- Aldo Badiani (Sapienza University, Italy; University of Sussex, UK): COVID-19 prevalence in people with opioid use disorder.
- Amanda Roxburgh (Burnet Institute, Australia): The Impact of COVID-19 on Supervised Injecting Facilities in Australia.
Session 2: Compulsivity and behavioural addictions during COVID-19 (11:30–13:30, with breaks and discussion)
- Lucy Albertella and Erynn Christensen (Monash University, Australia): Behavioural addictions during COVID-19: Predictors of risk and resilience.
- Ornella Corazza (University of Hertfordshire, UK): The impact of Physical Distancing on Body Image, Exercise Addiction and the use of Performance and Image Enhancing Drugs.
- Zsolt Demetrovics (Centre of Excellence in Responsible Gaming, University of Gibraltar, Gibraltar; ELTE Eötvös Loránd University, Hungary): Changes in addictive and problematic behaviours in Hungary during the COVID-19-related lockdowns.
- Anders C Håkansson (Lund University, Sweden): COVID-19, changes in gambling activity, and self-exclusion in Sweden.
Find out more about drug and behavioural addictions: Covid-19 and beyond.
Conference: Intoxication, Addiction and the Criminal Law
Saturday 13th January 2018, 9:00 - 17:30; Conference Centre, Bramber House, University of Sussex
Co-Hosted by the Sussex Crime Research Centre (CRC) and Sussex Addiction Research and Intervention Centre (SARIC).
The conference brings together international experts from across law, philosophy and neuroscience to discuss intoxicated and/or addicted offenders. We will investigate the impact of intoxication on the brain of a defendant, and how this links with increased criminal behaviour. We will analyse the legal response to intoxicated offenders who lack 'mental fault' due to their state of intoxication, questioning what the legal response should be. And we will explore the complicating factor of addiction, understanding the physical and mental impacts of the disease, and how (if at all) this affects/should affect criminal responsibility.
Session 1: Intoxication and culpability
Acute and chronic effects of alcohol on cognitive and emotional processes
Dora Duka, Professor of Experimental Psychology, University of Sussex, UK
People have used alcohol since earliest time to feel happy relaxed or creative. Alcohol induces elation and pleasure but at the same time it impairs memory and dampens our ability to control our behaviour. With its effects on memory alcohol reduces the ability to retrieve material encoded during intoxication thus leading to forgetting all unpleasant consequences of intoxication during periods of abstinence. During intoxication, on the other hand, alcohol impairs the ability to plan, to make efficient decisions, and to inhibit inappropriate responses, all functions contributing to the unpleasant consequences of intoxication. Data on the acute effects of alcohol on memory and cognitive control as well as on mood and sensitivity to reward will be presented. The contribution of these effects to risky and aggressive behaviours following alcohol binges will be discussed.
Neurobiological and cognitive consequences of acute and chronic drugs: A focus on cannabinoids
Valerie Curran, Professor of Psychopharmacology, University College London, UK
In this talk we will consider the increasingly blurred divide between illicit drugs and potential medicines. I will briefly describe the current uses of ketamine and its acute and chronic cognitive effects. The focus will then switch to cannabis. Cognitive effects – acute, chronic and residual – will be summarised before introducing the issue of individual differences and question why some are more vulnerable or resilient to the harms of cannabis. Two particular areas of our recent research will be highlighted: acute effects of cannabis in adolescents as compared with adults; effects of varying types of cannabis on the brain and cognition.
Intoxication and culpability
Douglas Husak, Professor of Philosophy, Rutgers University, US
I tackle the difficult problem of specifying how voluntary intoxication affects criminal culpability generally and recklessness in particular. I contend that the problem need not be conceptualised as an instance of actio libera in causa, namely the situation in which persons do something at t1 to culpably create the conditions of their own defense at t2. Instead, I argue that we need only consider intoxicated defendants at t2 in order to justify their punishment. In the course of defending my view, I challenge conventional wisdom about both the nature of recklessness and the effects of intoxicants. I conclude by discussing a possible ground on which involuntary intoxication might be treated differently.
Drug addiction is a brain disease but not a drug induced brain disease
Aldo Badiani, Professor of Psychology and Addiction Medicine, University of Sussex, UK
Repeated use of addictive drugs can produce neuroplastic changes in the cortical areas that exert inhibitory control over the reward circuits of the brain. Thus, many experts think that loss of control over drug use, hence drug addiction, is the result of drug-induced damage of the cortex. Furthermore, these drug-induced changes are thought to persist into prolonged abstinence explaining the chronic relapsing nature of drug addiction. In my presentation I will argue that, despite its popularity, the notion of addiction as a drug-induced disorder of the cortex (which is often presented as a fact rather than a hypothesis) is not supported by available evidence.
Innate vulnerability mechanisms in stimulant addiction
Jeff Dalley, Professor of Psychology and Neuroscience, University of Cambridge, UK
Addiction is a non-random brain disorder that afflicts a relatively small but stable proportion of individuals across the life span. Although we broadly understand how drugs abused by humans reinforce behaviour and alter subjective mood states there is no clear consensus on how extended drug use narrows or channels behaviour in addiction, especially in individuals who must surely be aware of the personal and wider harms of their behaviour. This talk addresses what is presently known about individual vulnerability to addiction, drawing on evidence from humans addicted to drugs as well as translational imaging and genetic approaches that reveal novel mechanisms and strategies to promote abstinence. Emphasis will be placed on behavioural traits (e.g. anxiety, impulsivity, sensation-/novelty-seeking) and underlying brain disorders that collectively accelerate the development of addiction.
What effect should intoxication have on criminal liability?
Paul H. Robinson, Colin S. Diver Professor of Law, University of Pennsylvania Law School, US
Professor Robinson will provide an overview of the legal issues relating to intoxication: the effect of voluntary intoxication in imputing to an offender a required offense culpable state of mind that he may not actually have had at the time of the offense; the effect of involuntary intoxication in providing a defense by negating a required offense culpability element or by satisfying the conditions of a general excuse; the legal distinction between voluntary and involuntary intoxication; the legal effect of alcoholism or addiction in rendering intoxication involuntary; and the limitation on using alcoholism or addiction in this way if the offender can be judged as reasonably responsible for creating his own addiction. Robinson will note some of the differences between the US and UK approaches on these issues.
No penal principle is sacred: Impacts of a failed approach to intoxicated offenders
Susan Dimock, Professor of Philosophy, York University, CA
Canada follows the (dubious) precedent laid down in DPP v Beard (1920), thereby separating crimes into specific intent or general intent offences. That an offender was intoxicated at the time of their crime is said to be potentially relevant to specific intent crimes and so its impact on an accused’s state of mind at that time can be considered in establishing the mental elements necessary for conviction. An offender’s intoxication is considered irrelevant in the case of general intent crimes, by contrast, and so cannot be considered. I continue my assault on this unacceptable legal practice, showing that it leads to the violation of virtually every principle of penal justice: from fundamental principles of statutory interpretation to the presumption of innocence.
The effect of alcohol and drugs on memory for criminal offences
Kim van Oorsouw, Assistant Professor and Legal Psychology Track Coordinator, Maastricht University, NL
About 25-45% of offenders claim (partial) amnesia for their crime due to intoxication. Sometimes full-blown amnesia is reported after large amounts of alcohol were consumed. What do we know about the effect of alcohol and drugs on memory? Is it possible to forget a highly emotional event while intoxicated? When assets are at stake, claims of amnesia might be feigned. This presentation will give an overview of what we know about memory for events that took place while intoxicated. Recent research findings will be presented. In addition, a case will in which an offender claims complete memory loss for murder will be discussed. It will show how legal psychologists deal with claims of amnesia to determine whether the blackout is genuine or feigned.
The fault factor in automatism and insanity
Ronnie Mackay, Professor of Criminal Policy and Mental Health, De Montfort University, UK
Should the criminal law have a broader notion of fault liability rendering a defendant liable to conviction for a criminal offence which extends beyond that of self-induced intoxication? In this connection the law surrounding automatism has been slow to develop, perhaps betraying some confusion and even reluctance to accept such a notion.
In addition, the defence of insanity, which encompasses insane automatism, has always been viewed as being outside the doctrine of prior fault. But is this approach still tenable?
This paper will assess whether the current status of the “fault factor” in both automatism and insanity needs to be re-evaluated.
A new prior fault offence: The challenge ahead 
Sussex Prior Fault Project Team: John Child, Hans Crombag, Rudi Fortson QC
The concept of prior-fault allows for the usual offence-event focus of criminal liability (t2) to be expanded in certain cases to take account of a defendant’s (D’s) previous conduct (t1). For example, D becomes voluntarily intoxicated at a public house, falls over and causes damage to a table. When charged with criminal damage, D may plausibly deny the mental element of the offence on the basis that she was ‘too drunk to understand the risks’ of her conduct when falling at t2, but prior-fault intoxication rules will apply to find liability, reconstructing her missing mental element based on her prior-fault in getting voluntarily intoxicated at t1.
Such rules, often (though incorrectly) discussed as criminal defences, can arise in the context of prior-fault intoxication, prior-fault automatism, prior-fault insanity, as well as in the application of defences properly so called (eg, where D acts in self-defence based on an intoxicated mistake). Crucially, the legal rules applicable in each area have developed haphazardly, inconsistently, and lacking in basic theoretical coherence, with each subject to recent attention and critique from the Law Commission.
We explore options for reform, and in particular the option most commonly highlighted in the literature, the potential for replacing the current matrix of rules with a new prior-fault offence.Although mooted in the context of prior-fault intoxication for over forty years, only a handful of proposals have ever been fully defined and presented, and each one has been rejected as unworkable: unworkable because of theoretical incoherence, problems in practical application (particularly courtroom procedures), and/or complex interlocking issues of addiction and mental illness. Rather than ignoring or side-lining such complex problems, the purpose of our project is to explore each in detail, looking for solutions and ways forward.
Conference Organisers:
John Child, Senior Lecturer in Law, University of Sussex
Hans Crombag, Senior Lecturer in Psychology, University of Sussex
Stavros Demetriou, Lecturer in Law, University of Sussex
Seminars
Neuroscience in criminal law: using addiction as an example
Thursday, 08 December 2022, 13:00-14:00 - Fulton Building (Room 201), University of Sussex
Dr Anna Goldberg
Vrije Universiteit Amsterdam
With an increase of neuroscientific techniques and insights over the past decades, including neuropsychological developments, the potential relevance thereof for (criminal) law has not gone unnoticed. The academic discipline neurolaw aims to explore the potential impact of neuroscience on the law, and research in this discipline can be roughly divided into three approaches. First, scholars discuss the role of neuroscience in addressing an individual’s liability: an individual, or micro level approach. A more collective (or meso-level) approach would rather assess the influence of neuroscientific evidence or perspectives on the perception and capacities of a particular group of people or a general (mental/physical) condition. Lastly, a structural or macro-level approach can be taken, to examine the potential of neuroscience to change the legal framework as we know it.
During the colloquium talk, I will discuss these three approaches in some more detail, using addiction as an example. Our understanding of substance use disorders has changed drastically when the contribution of brain processes, and the prolonged neural consequences of substance use, were taken into account. Hence, addiction is a great example to discuss the consequences of neuroscientific insights onto the law, by studying whether the approach towards addicted offenders have been affected by such an increased neuroscientific understanding. Before going into detail, a basic introduction to criminal liability as well as to addiction will be provided, meaning no prerequisite knowledge of either field is required.
Host: Dr Paloma Manguele.
Find out more information about the research conducted by Dr Anna Goldberg.
L-type calcium channel regulation of dopamine and motivated behavior in preclinical models of substance use and mood disorders.
Monday, 31 January 2022, 16:00-17:00 - SARIC Virtual Seminar, Zoom, University of Sussex
Dr Nii Addy
School of Medicine
Yale, USA
Dr. Addy’s research focuses on the neurobiological processes underlying substance use disorders, mood disorders, and comorbid substance use and mood disorders. Dr. Addy’s team uses multiple methodologies, including behavioral paradigms such as intravenous drug self-administration, acute and chronic stress paradigms, and anxiety and amotivation paradigms, along with integrated pharmacological, in vivo electrochemical, and in vivo optogenetic methods to investigate these mechanisms. Dr. Addy will present his preclinical findings, revealing cholinergic and L-type calcium channel processes in the mesolimbic dopamine reward system that robustly mediate substance use and mood disorder behavioral phenotypes through regulation of dopaminergic activity. Dr. Addy will also describe ongoing work with potential therapeutic compounds, targeting subtype-specific muscarinic receptors and L-type calcium channels. He will describe upcoming clinical collaborative studies, based on his team’s recent preclinical findings. Finally, Dr. Addy will discuss his career journey as an academic researcher, mental health advocate, diversity equity and inclusion leader, and host of the Addy Hour podcast.
Host: Dr Bryan Singer
Find out more information about the research conducted by Dr Nii Addy.
Basal differences and diet-induced changes in motivation and striatal function; implications for obesity
Tuesday, 02 March 2021, 14:00-15:00 - SARIC Virtual Seminar, Zoom, University of Sussex
Monday, 26 April 2021, 13:00-14:00 - SARIC Virtual Seminar, Zoom, University of Sussex
Dr Carrie Ferrario
Department of Pharmacology
University of Michigan, USA
In recent years, Dr Ferrario has won numerous Young Investigator awards for her work on the neurobiology of drug addiction and obesity (with a focus on glutamatergic plasticity). Her lab successfully integrates various preclinical research approaches (e.g., chemo- and optogenetics, electrophysiology, biochemistry, complex behavioural analyses).
Host: Dr Bryan Singer
Find out more information about the research conducted by Dr Carrie Ferrario.
Unlocking the neurobiological impact of developmental cannabis and psychiatric risk
Tuesday, 02 March 2021, 14:00-15:00 - SARIC Virtual Seminar, Zoom, University of Sussex
Dr Yasmin Hurd
Director, Addiction Institute
Icahn School of Medicine at Mount Sinai, USA
The sociopolitical landscape has dramatically changed worldwide regarding the medical and recreational use of cannabis. This talk will provide insights about advances made about the neurobiological underpinnings of developmental cannabis/THC exposure that maintains a long-term impact on adult behavior. The research describes translational and multidisciplinary scientific approaches ranging from molecular, epigenetic and behavioral studies in animal models as well as human clinical studies.
Host: Dr Bryan Singer
Find out more information about the research conducted by Dr Yasmin Hurd.
Risk-tolerant inter-temporal preferences, serotonergic receptor activity and temporal-difference learning in humans and mice
Thursday, 18 February 2021, 13:00-14:00 - SARIC Virtual Seminar, Zoom, University of Sussex
Prof Robert Rogers
School of Psychology
Bangor University, UK
Preferences for variable over fixed delay schedules are consistently observed across species, reflecting risk-tolerant biases that prioritise obtaining food resources at the earliest possible opportunity. Here, we investigated this issue by asking young healthy adults to make decisions about when they might next eat highly palatable food rewards. We show that preferences for instrumental contingencies involving consumed-on-the-spot food rewards involve the incremental computation of action-values that are powerfully moderated by recent experiences of quick food rewards; that these computations are moderated by motivational state and link directly to peoples evaluation of actions involving foods, their behaviour in making food selections and their broader eating experiences. We also validate these findings in mice, demonstrating inter-temporal biases are modulated by 5-HT2c receptor activity function and involve the operation of parallel learning and evaluative mechanisms cross-species.
Host: Dr Bryan Singer
Find out more information about the research conducted by Prof Robert Rogers.
Reverse translation to study drug addiction and identify new brain mechanisms
Monday, 08 February 2021, 15:00-16:00 - SARIC Virtual Seminar, Zoom, University of Sussex
Dr Marco Venniro
Department of Anatomy and Neurobiology
University of Maryland School of Medicine, USA
The goal of our research, and of the addiction field in general, has not merely been to identify neuropharmacological and circuit mechanisms of drug addiction and relapse. The goal was to achieve prospective predictive validity—the ability to identify new treatments. As I will describe in the lecture, the classical relapse model in its traditional form has not appreciably changed the options available to patients in need of relapse prevention. This shortcoming is not unique to relapse, but it is an increasing source of disappointment, and it calls for a regrouping.
In our laboratory, we have regrouped by developing a set of approaches that begin with reverse translation. As a first step, we have mimicked behavioral treatments that are largely successful in humans: contingency management, and community-reinforcement approach. None of these treatments is universally effective in the clinic, and, this, too, can be modelled in our rats. These reverse-translated “treatments” are an ecologically relevant platform from which we can move on to translation itself, using different methods to discover new relapse-related circuits and to identify new medications for relapse prevention in “treated” or post-“treated” rats. In the lecture, I will introduce these animal models, describe our initial pharmacological and circuit results, and discuss implications for treatment.
Host: Dr Silvana De Pirro
Find out more information about the research conducted by Dr Marco Venniro.
Neuronal encoding of drug choices and preference in the orbitofrontal cortex
Monday, 07 December 2020, 13:00-14:00 - SARIC Virtual Seminar, Zoom, University of Sussex
Dr Karine Guillem
CNRS, Institut des Maladies Neurodégénératives
Bordeaux Neurocampus, France
Human neuroimaging research has consistently shown that drug addiction is associated with structural and functional changes within the orbitofrontal cortex (OFC). In view of the important role of the OFC in value-based decision-making, these changes have been hypothesised to bias choice towards drug use despite and at the expense of other competing pursuits, thereby explaining drug addiction. Here I will present in vivo recording data in the OFC supporting this hypothesis in a choice-based model of addiction where rats could choose between two actions, one rewarded by a drug (cocaine or heroin), the other by a nondrug alternative.
Host: Dr Eisuke Koya
The endocannabinoid system as a mediator of stress and reward processing in humans: implications for clinical treatment
Monday, 30 November 2020, 13:00-14:00 - SARIC Virtual Seminar, Zoom, University of Sussex
Dr Leah Mayo
Assistant Professor, Center for Social and Affective Neuroscience
Linköping University, Sweden
The endocannabinoid system is a neuromodulatory system implicated in a range of behaviors, including stress, affect, and reward processing. As such, it has been proposed as a novel therapeutic target for stress-related psychiatric disorders. In particular, enhancing endogenous cannabinoid signaling through inhibition of primary degradative enzymes may offer an efficacious treatment strategy with fewer detrimental side effects. To better understand how these pharmacological interventions may prove useful, we have begun to characterise endocannabinoid function in human behavior.
This presentation will summarise studies assessing endocannabinoid function in affect and reward processing in humans, particularly in the context of environmental challenges such as stress or alcohol exposure. Evidence will come from studies employing an array of methodological approaches, including behavioral, psychophysiological, pharmacological, and neuroimaging methods. The presented data will help delineate evidence-based therapeutic opportunities for leveraging cannabinoid function to treat psychiatric disease.
Host: Dr Bryan Singer
Find out more information about the research conducted by Dr Leah Mayo.
Vulnerability to Developmental Effects of Drugs of Abuse in Adolescence: Who, When and How?
Monday, 23 November 2020, 14:00-15:00 - SARIC Virtual Seminar, Zoom, University of Sussex
Professor Cecilia Flores
Department of Psychiatry
McGill University, Canada
Adolescence is an age of increased vulnerability to addiction, but we still know very little about the cellular and molecular processes ongoing during adolescent brain development and how they are influenced by drugs of abuse. This talk focuses on the emerging role of axonal guidance cues in the maturation of the prefrontal cortex in adolescence and its implications for psychiatric susceptibility and resilience. Drugs of abuse target guidance cue systems in adolescence, altering the organisation of prefrontal cortex connectivity and cognitive function in adulthood. The impact of these effects is sexually dimorphic and depends on the specific adolescent period.
Host: Dr Bryan Singer
Find out more information about the research conducted by Professor Cecilia Flores.
Synaptic mechanisms maintaining persistent cocaine craving
Monday, 16 November 2020, 16:30-17:30 - SARIC Virtual Seminar, Zoom, University of Sussex
Professor Marina Wolf
Professor of Behavioral Neuroscience, School of Medicine;
Oregon Health and Science University, United States
The major challenge in treating drug addiction is that recovering addicts remain vulnerable to drug craving and relapse even after long periods of abstinence. The goal of the Wolf lab is to understand synaptic mechanisms that maintain this persistent vulnerability to relapse.
Most of our studies use the incubation of craving model. Incubation refers to the progressive increase in cue-induced craving that develops after discontinuing drug self-administration. Craving remains at high (incubated) levels for months. Incubation of craving also occurs in humans.
Our work has focused on excitatory synapses in the nucleus accumbens, a key brain region for motivated behavior. My talk will describe published and unpublished work showing profound alterations in all of the major glutamate receptors in the NAc (AMPA, NMDA and metabotropic glutamate receptors) after incubation of cocaine craving and discuss predicted consequences for information processing in the NAc.
Host: Dr Bryan Singer
Find out more information about the research conducted by Professor Marina Wolf.
Helping people with alcohol problems in India by giving psychology away: Revisiting western challenges and solutions in low and middle income countries
Wednesday, 21 October 2020, 16:00-17:00 - SARIC Virtual Seminar, Zoom, University of Sussex
Professor Richard Velleman
Co-Director, Addictions Research Group and Senior Research Fellow, Sangath Community Health NGO, Goa, India;
Emeritus Professor of Mental Health Research, University of Bath, UK
I’ve always been interested in ‘giving psychology away’ and have in my career developed interventions for use by both specialists and non-specialists alike. More recently, I have tried to take these ideas a few steps further, seeing if one can use the same principles to try to make changes on a global canvas, especially in Low and Middle Income Countries (LMICs), where the challenges are generally far greater.
10 years ago I joined an NGO named Sangath, in Goa, India, which is committed to undertaking research to improve mental health by developing appropriate psychological and social therapies and pioneering and researching ways of making mental healthcare more accessible and affordable for the wider community. Sangath was set up and run for many tears by Prof Vikram Patel, one of the leading figures in Global Mental Health (https://www.hsph.harvard.edu/vikram-patel/ and see his TED talk: https://www.ted.com/speakers/vikram_patel) although he is less involved now than he was. 5 years ago within Sangath I formed (with one of my colleagues there) the Addictions Research Group, and at the moment I am engaged in a number of major projects, most based in Goa in India, but with some being replicated or scaled up in other areas of India, and all with the potential to cover a much wider range of LMICs. My role within Sangath is to bring these ‘giving psychology away’ ideas to the organisation, and to mentor senior staff to obtain research grants and write papers so that Sangath continues to grow and develop in the post-Vikram-Patel era.
This presentation will introduce a number of the projects we have developed, and will go into more detail about one or two, especially the Premium Project, with some information about how the interventions developed for that project are starting to be utilised in other LMICs. It will also outline some of the key approaches we are using to ‘give addiction studies away’ to others within LMICs.
Host: Dr Bryan Singer and Dr Daniel Michelson
Find out more information about the research conducted by Professor Richard Velleman.
Liking and wanting in the brain
Thursday, 17 October 2019, 14:00-15:00 - School of Psychology Colloquia, The Meeting House, University of Sussex
Professor Kent Berridge
James Olds Distinguished University Professor of Psychology and Neuroscience Department of Psychology;
University of Michigan, USA
Liking and wanting usually go together for pleasant rewards, but turn out to have separable brain mechanisms.
Addictions may arise from this liking/wanting separation. ‘Liking’ is generated by a surprisingly frail and tiny network of hedonic hotspots in brain limbic structures. ‘Wanting' for the same pleasures has a much more robust and larger brain network involving dopamine systems. Surprisingly, the ‘wanting’ system also may have a paradoxical relation to fear. The relation between liking, wanting, and fear systems has further implications for understanding clinical disorders beyond addiction, including depression and schizophrenia.
Host: Professor Aldo Badiani
Find out more information about the research conducted by Professor Kent Berridge.
Sensitisation, uncertainty, and drug taking
Thursday, 12 September 2019, 14:00-15:00 - School of Psychology Colloquia, Pevensey 1 - 2D11, University of Sussex
Professor Paul Vezina
Department of Psychiatry and Behavioral Neuroscience;
The Univerisity of Chicago, USA
I will present some of our work showing how sensitisation promotes drug taking and how changes in dopamine-glutamate signaling in the ventral forebrain mediate this effect. I will also describe our recent work exploring behavioral and neurochemical commonalities between the effects of drug sensitisation and those produced by repeated intermittent exposure to conditions of uncertainty, as experienced in games of chance.
Our goal is to understand how altered activity in the neurotransmitter circuits of the basal ganglia contributes, with its psychological complements, to both drug and behavioral addictions such as gambling disorder.
Host: Professor Aldo Badiani
Find out more information about the research conducted by Professor Paul Vezina.
Psychosocial pathways in addiction: brain structure, function, and putative underlying neuroimmune mechanisms
Thursday, 16 May 2019, 14:00-15:00 - School of Psychology Colloquia, Pevensey 1 - 1A6, University of Sussex
Dr. Keren Bachi
Department of Psychiatry
Department of Environmental Medicine and Public Health
The Addiction Institute of Mount Sinai
Icahn School of Medicine at Mount Sinai, New York, USA
Impairments in social cognition and functioning are recognised as core illness features associated with atypical brain function in multiple neuropsychiatric illnesses.
Increasingly, impairments in social information processing have also been implicated as core symptoms of drug addiction, whereby the brain regions engaged by social cognition in healthy individuals (e.g., prefrontal cortex, superior temporal sulcus, temporoparietal junction, amygdala, hippocampus, anterior cingulate cortex, and the temporal poles) are implicated in the pathophysiology of drug addiction. Hence, addiction impacts the very same circuits that enable self-monitoring and complex social functioning. Individuals with substance use disorder frequently experience social stress (e.g., childhood maltreatment) which may shape neural and physiological responses to social interactions and exacerbate illness risk.
However, to date, studies of the neural correlates of social cognition in addiction are limited, and specifically literature about the brain function underlying social information processing in individuals with cocaine use disorder remains in its infancy. Knowledge regarding the neural underpinnings of social cognition/function in this population can help to facilitate treatment efficacy and recovery.
This presentation will summarise multimodal imaging and behavioral findings, including childhood trauma effects on gray matter in orbitofrontal cortex of cocaine addicted individuals and observed associations with psychological comorbidity.
Our findings further demonstrate aberrant neural correlates of mentalising (social inference) and social navigation as associated with severity of drug dependence and social functioning in this population.
I will also discuss how via activation of sympathetic stress systems and the hypothalamic-pituitary-adrenal axis, immune dysregulation may provide a psychobiological link between chronic social stress, deficits in mentalising and social processing and drug addiction.
Host: Professor Aldo Badiani
Find out more information about the research conducted by Dr Keren Bachi.
Drug addiction is a disorder of excessive goal-directed choice in negative affective states, not habit or compulsion
Thursday, 9 May 2019, 14:00-15:00 - School of Psychology Colloquia, The Meeting House, University of Sussex
Dr. Lee Hogarth
Department of Psychology
University of Exter, UK
Addiction may be driven by excessive valuation of the drug as the goal of intentional choice (especially in negative affect states), or a habit driven by strong stimulus-response associations, or a compulsion driven by discounting (neglecting) costs imposed on drug-seeking.
The human studies described in this talk favour the excessive goal-directed choice account and contradict the habit and compulsion accounts. Contradicting habit theory, a series of human outcome-devaluation studies failed to demonstrate a predilection for habit learning in treatment-seeking addicts or students with greater dependence symptoms. Contradicting compulsivity theory, sensitivity to costs imposed on drug-seeking is comparable across levels of dependence symptom severity.
By contrast, dependence symptom severity in clinical and sub-clinical samples is reliably associated with greater goal-directed choice of the drug over alternative rewards (as demonstrated in outcome devaluation procedures). Furthermore, negative mood and stress states augment goal-directed drug choice, and individuals who report psychiatric symptoms and substance use to cope with negative affect are more sensitive to these induction effects.
Finally, substance use to cope with negative affect statistically mediates the relationship between psychiatric symptoms and substance dependence severity. Together, these studies suggest that drug dependence is not driven by habit or compulsion, but by excessive valuation of the drug as the goal of voluntary choice, especially during negative affective states in those with psychiatric comorbidity. Implications for optimising addiction treatment are discussed.
Host: Professor Dora Duka
Find out more information about the research conducted by Dr Lee Hogarth.
Brains, drugs, and public policy
Tuesday, 7 May 2019, 13:00-14:00 - Sussex Neuroscience Seminar Room, CRPC Building 4.03, University of Sussex
Professor Keith Humphreys
Professor and Section Director for Mental Health Policy
Department of Psychiatry and Behavioral Sciences
Standford University, USA
The regulation of alcohol, tobacco, opioids, and other addictive drugs is fundamentally political but can be informed by research findings, certainly including those from neuroscience.
Neuroscience has made enormous progress in describing the impact of addictive drug consumption on the brain, including its decision-making apparatus.
However, the lead causes of addiction at the population level in the past 150 years emerge from outside the brain, namely in a substance saturated environment which human beings are poorly equipped by evolution to negotiate. This implies that public health and safety regarding drug can best be maximised by applying the lessons of neuroscience and related fields to policies regarding drug availability and the treatment of addiction.
That said, all policies around drugs let societies choose what type of drug problem they want to have; no policy will eliminate the problem either in absolute terms or with the perspectives of all observers.
Dr Humphreys will illustrate these points both with reference to the scientific literature and to his experiencing advising the U.S. and U.K. governments.
Host: Dr Silvana De Pirro and Professor Aldo Badiani
Find out more information about the research conducted by Professor Keith Humphreys.
Predisposition to addiction – Clues from longitudinal MRI and translational neuroscience
Monday, 24 September 2018, 13:00-14:00 - Sussex Neuroscience Seminar Room, CRPC Building 4.03, University of Sussex
Professor Jeff Dalley
Department of Psychiatry and Psychology
Behavioural and Clinical Neuroscience Institute
University of Cambridge, UK
Addiction to various classes of abused drug (stimulants, alcohol, opioids) mysteriously afflicts some but not all individuals.
Notwithstanding the evident complexity and idiosyncratic nature of addiction many now accept that distinctive neurobehavioural endophenotypes make unique contributions to the various stages of addiction – from initiation and recreational drug use to increasing levels of consumption involving repeated bouts of intoxication, withdrawal and relapse. Although research in experimental animals has increased our understanding of addiction beyond ‘simple’ reinforcement mechanisms, debate still surrounds the validity and translation of such findings (mainly in rodents) to real-world addiction in humans.
This talk reflects on: (i) the so-called translational divide in addiction research, in particular the strengths and weaknesses of categorising putatively causal traits (anxiety, impulsivity, incentive conditioning, novel seeking and preference) to aspects of addiction; (ii) the inference of ‘addiction’ in experimental animals, and (iii) how progress in this field has been advanced by the translational methodologies of MRI and PET.
Host: Dr. Ilse Pienaar
Find out more information about the research conducted by Professor Jeff Dalley.
The DREADDed Weed: Chemogenetic dissection of dopamine function after adolescent cannabinoid exposure
Friday, 7 September 2018, 14:00-15:00 - John Maynard Smith (JMS) Building, room 4D13 University of Sussex
Dr. Steve Mahler
Department of Neurobiology and Behaviour
University of California, Irvine, USA
Adolescence is a critical window of maturation for reward-related brain circuits, which is in part orchestrated by endocannabinoid (ECB) signaling.
Exogenous perturbation of cannabinoid transmission with drugs like cannabis during adolescence may therefore have consequences on mesolimbic reward circuit development, and persistently alter motivated behavior into adulthood. ECB signaling regulates ventral tegmental area (VTA) dopamine (DA) projections to forebrain regions like nucleus accumbens (NAc) and dorsal medial prefrontal cortex (dmPFC), yet it remains unclear how exogenous cannabinoid receptor stimulation during adolescence alters DA circuits, and DA-dependent behaviors.
Here, I discuss our recent dissections of DA system function in adult tyrosine hydroxylase: Cre (TH:Cre) rats following adolescent dosing with a rewarding cannabinoid drug, and find several long-lasting alterations in DA stimulated endocannabinoid transmission, neural activity in reward circuits, and motivated behavior.
Our results reveal that adolescence is a critical window of development during which even small doses of cannabinoids drugs can persistently alter mesolimbic DA circuit neural and endocannabinoid activity, causing potentiated reward-seeking behaviors that could increase vulnerability to later-life addiction or other psychiatric disorders.
Host: Dr. Eisuke Koya
Find out more information about the research conducted in the Mahler Lab.
Losing control: alcohol, glutamate and the prefrontal cortex
Thursday, 26 July 2018, 13:00-14:00 - Sussex Neuroscience Seminar Room, CRPC Building 4.03, University of Sussex
Professor Wolfgang Sommer
Professor for Psychiatry at the University of Heidelberg,
Chair of the Department of Addiction Medicine,
Deputy director of the Institute for Psychopharmacology
Central Institute for Mental Health in Mannheim, Germany
The medial prefrontal cortex (mPFC) is critically involved in cognitive flexibility and top down control over behavior in both in humans and animals. How these mPFC functions are organised and implemented on the neural level is so far unknown.
Importantly, mPFC function is progressively compromised by chronic or excessive alcohol consumption. A potential pathomechanism underlying the alterations in neuronal function is dysregulation of glutamatergic neurotransmission.
Among these alcohol-induced changes is a long-lasting deficit of metabotropic glutamate receptor 2 (mGluR2) in mPFC neurons of both humans and rodents. This deficit comprises a common pathological mechanism for excessive alcohol cue reactivity and impaired cognitive flexibility as demonstrated in rat models of cue-induced alcohol seeking and attentional set shifting, respectively.
To further understand how the mPFC exert control over behavior, we have developed methods for tracing and manipulating the activity state of the glutamatergic neurons.
We found that distinct sets of neurons in the mPFC play a key role in alcohol seeking. To further investigate the dynamics of local networks within mPFC and their relation to the expression of alcohol seeking behaviors we are currently setting up microendoscopic calcium imaging of neuronal activity in freely moving rats.
According to Hebb’s concept of neuronal ensembles, specific sets of neurons may interact in the storage and processing of memories, and this principle has recently been demonstrated for the pursuit of several drug or natural rewards. Initial results will be discussed in the context of ensemble concept and for their potential ramifications to alcohol use disorders.
Host: Professor Dora Duka
Drugs and harm reduction: Has the UK lost its crown?
Wednesday, 30 May 2018, 17:30-18:30 - Fulton B Lecture Theatre, University of Sussex
Rudi Fortson QC
Visiting Professor of Law
Queen Mary University
Indipendent practing Barrister
Sussex Prior Fault Team
The UK, which was once a pioneer and leader in the field of drug harm-reduction, is now falling behind other countries.
The Misuse of Drugs Act 1971, which has often been criticised as an instrument of prohibition, was designed to be regulatory and sufficiently flexible to respond to harmful effects of drug use that are sufficient to constitute a social problem.
In the event, the intensity of UK drug laws has increased while the incidence of recreational and problematic drug use remains high. Harm reduction initiatives such as onsite drug checking, supervised drug consumption facilities, and the prescription or licensing of cannabis for medicinal purposes, encounter significant legal problems.
However – as this talk will demonstrate - there is increasing goodwill between agencies in the public and private sector to promote and to practice harm-reduction measures in the interests of personal and public health.
These findings suggest that the CeA is involved with assigning increasing value to reward and directing decision-making by generating narrowly focused motivation to seek out reward that may persist in the face of more rewarding alternatives and adverse consequences.
Host: Dr. Hans Crombag
Optogenetic activation of the central amygdala generates individual differences in compulsive reward seeking despite adverse consequences
Friday, 27 April 2018, 13:00-14:00 - Ashdown House Room 102, University of Sussex
Dr. Mike Robinson
Assistant Professor of Psychology, Neuroscience and Behaviour
Department of Psychology
Wesleyan University, CT, USA
Drug and behavioural addictions are characterised by focused pursuit of a single reward above all others. Excessive motivation to pursue reward leads to persistent addictive-like decisions that often undermine an individual’s best interests, and prevail despite adverse consequences.
The amygdala plays a key role in reward processing and generating motivation. In the following studies, we explored how optogenetic stimulation of the central amygdala (CeA) modulates decision-making and reward choice, causing specific rewards to be almost compulsively preferred in manners that model many of the DSM criteria for addiction.
Rats were trained to choose between a reward paired with CeA laser stimulation or an otherwise unpaired identical or alternative reward. Rats developed a nearly exclusive preference for the CeA laser-paired reward over the unpaired reward. This was true whether the reward was a sucrose pellet or an infusion of cocaine.
For sucrose, this preference persisted even when a much larger sucrose reward was offered as an alternative, or when the preferred reward was paired with an electric footshock. CeA laser stimulation also produced persistent pursuit of a flavored reward paired with conditioned taste aversion. For cocaine, CeA laser stimulation produced an escalation of cocaine intake, and compulsive nibbling of the nose port paired with laser-associated cocaine, as though seeking more. For both cocaine and sucrose, CeA stimulation dramatically increased an animal’s motivation for the laser-paired reward over an otherwise identical unpaired reward. In each case, these effects were not the consequence of any independently rewarding properties of optogenetic activation of the CeA alone.
These findings suggest that the CeA is involved with assigning increasing value to reward and directing decision-making by generating narrowly focused motivation to seek out reward that may persist in the face of more rewarding alternatives and adverse consequences.
Host: Dr. Hans Crombag
Dopamine transmission, dendritic plasticity, and the attribution of incentive value to salient reward-predictive stimuli
Monday, 22 January 2018, 13:00-14:00 - Sussex Neuroscience Seminar Room, CRPC Building 4.03, University of Sussex
Dr. Bryan F. Singer
Lecturer in Psychology, Life, Health & Chemical Sciences
Faculty of STEM
The Open University, Milton Keynes, UK
There is considerable individual variation in the degree to which cues exert motivational control over behaviour, and we have been able to model this diversity in rodents. Specifically, we have found that when a lever conditioned stimulus (CS) predicts food reward, outbred rats differ in the exact conditioned response they learn and perform. For some rats, the lever-CS becomes “wanted” – these “sign-tracker” (ST) rats approach the lever and interact with it until the reward is delivered. In contrast, “goal-tracker” (GT) rats orient to the lever-CS, but do not interact with it and instead approach the location of food delivery.
Individual variation in dopamine (DA) neurotransmission and uptake contribute to this variation in the extent to which reward cues acquire motivational value. We are also investigating how this variation in DA transmission impacts dendritic changes associated with learning and memory. Finally, we are developing new tools for detecting variation in cue-evoked motivation in people.
Altogether, we hope to find ways to identify and reduce the motivational power of reward-paired cues in certain individuals, and this may prove to be useful for combatting disorders ranging from food addiction to substance abuse.
Host: Professor Aldo Badiani
Affective memories associated with withdrawal in opiate dependence: From cellular imaging to in vivo recordings
Monday, 4 December 2017, 13:0-14:00 - Sussex Neuroscience Seminar Room, CRPC Building 4.03, University of Sussex
Dr. Catherine Le Moine
Neuropsychopharmacology of addiction
Research Director, INCIA (Aquitaine Institute for Cognitive and Integrative Neuroscience)
University of Bordeaux, France
Host: Dr. Eisuke Koya
Your brain on drugs: Not the same everywhere
Wednesday, 8 November 2017, 18:30-20:00 - Brighton and Sussex Medical School, Chowen Lecture Theatre, University of Sussex
Professor Aldo Badiani
Professor of Psychology and Addiction Medicine
Director, SARIC
School of Psychology
University of Sussex, Brighton, UK
Addictive drugs such as cocaine, heroin, or alcohol are often thought to be the same in their ability to produce ‘pleasure’ by activating the ‘reward’ circuitry of the brain.
In this lecture, I will show that different classes of drugs produce unique neurobiological effects and distinctive internal states, which in turn are exquisitely sensitive to the environment surrounding drug use.
Neuroimaging in drug addiction: an eye towards intervention purposes
Monday, 24 April 2017, 13:00-14:00 - Sussex Neuroscience Seminar Room, CRPC Building 4.03, University of Sussex
Professor Rita Z. Goldstein
Chief, Neuropsychoimaging of Addiction and Related Conditions (NARC) Research Program
and Brain Imaging Centre (BIC)
Department of Psychiatry and Department of Neuroscience,
Friedman Brain Institute
Icahn School of Medicine at Mount Sinai, New York, USA
Drug addiction is a chronically relapsing disorder characterised by compulsive drug use despite catastrophic personal consequences (e.g., loss of family, job) and even when the substance is no longer perceived as pleasurable.
In this talk, Dr. Goldstein will present results of human neuroimaging studies, utilising a multimodal approach (neuropsychology, functional magnetic resonance imaging, positron emission tomography, event-related potentials recordings), to explore the neurobiology underlying the core psychological impairments in drug addiction (impulsivity, drive/motivation, insight/awareness) as associated with its clinical symptomatology (intoxication, craving, bingeing, withdrawal).
The focus of this talk is on understanding the role of the dopaminergic mesocorticolimbic circuit, and especially the prefrontal cortex, in higher-order executive dysfunction (e.g., disadvantageous decision-making such as trading a car
for a couple of cocaine hits) in drug addicted individuals.
The theoretical model that guides the presented research is called iRISA (Impaired Response Inhibition and Salience Attribution), postulating that abnormalities in the orbitofrontal cortex and anterior cingulate cortex, as related to dopaminergic dysfunction, contribute to the core clinical symptoms in drug addiction.
Specifically, Dr. Goldstein’s multi-modality program of research is guided by the underlying working hypothesis that drug addicted individuals disproportionately attribute reward value to their drug of choice at the expense of other potentially but no-longer-rewarding stimuli, with a concomitant decrease in the ability to inhibit maladaptive drug use.
In this talk, Dr. Goldstein will also explore whether treatment (as usual) and 6-month abstinence enhance recovery in these brain-behavior compromises in treatment seeking cocaine addicted individuals.
Promising novel fMRI studies, which combine pharmacological (i.e., oral methylphenidate, or RitalinTM) and salient cognitive tasks or functional connectivity during resting-state, will be discussed as examples for using neuroimaging in the empirical guidance for the development of effective neurorehabilitation strategies in cocaine addiction.
Neuronal mechanisms of drug relapse after cessation of prolonged contingency management in a rat model
Monday, 24 October 2016, 13:00-14:00 - Sussex Neuroscience Seminar Room, CRPC Building 4.03, University of Sussex
Dr. Daniele Caprioli
Assistant Professor,
Department of Physiology and Pharmacology,
Sapienza University of Rome, Rome, Italy
Despite decades of research on the neurobiological mechanisms of psychostimulant addiction, the only effective treatment for many addicts is contingency management. In this behavioral method, the availability of non-drug rewards (e.g., monetary vouchers), given in exchange for being drug free (verified by drug testing), maintains prolonged abstinence in many psychostimulant addicts.
However, when contingency management is discontinued, most addicts relapse to drug use.The brain mechanisms underlying relapse after cessation of contingency management are unknown and until recently, an animal model of this human condition did not exist.
In the present lecture I will present a new choice-based rat model of relapse, along with its first neurobehavioral characterisation, in which Meth craving is observed after prolonged voluntary abstinence. Specifically I will provide evidences that relapse after voluntary abstinence from methamphetamine self-administration is mediated by (1) dorsomedial striatum neuronal ensembles that are comprised of heterogeneous D1- and D2-expressing neurons;
(2) anterior insula to central amygdala projections.
Stress-induced relapse to alcohol seeking: Back to the drawing board
Thursday, 6 October 2016, 15:00-16:00 - Sussex Neuroscience Seminar Room, CRPC Building 4.03, University of Sussex
Professor Markus Heilig
Director at the Center for Social and Affective Neuroscience,
Department of Clinical and Experimental Medicine,
Linköping University, Sweden
Progression into alcohol addiction is characterised by lasting changes in brain function. These result in escalated voluntary alcohol intake, alcohol seeking despite adverse consequences, and increased sensitivity to relapse triggered
by stress.
The neural substrates of these behavioral traits have remained unknown. We have found that a history of alcohol dependence results in DNA-hypermethylation selectively in the medial prefrontal cortex, leading to a persistent reprogramming of the mPFC transcriptome.
We have then identified an epigenetic enzyme, PRDM2, as a key mediator of these expression changes and their behavior consequences.
Our findings indicate that DNA-methylation mediated repression of PRDM2 is involved in multiple aspects of alcohol dependence, including stress-induced relapse, compulsivity-like behavior and escalation of alcohol intake.
Individual differences in dopamine transmission: A potential vulnerability pathway to addiction
Monday, 12 September 2016, 13:00-14:00 - Sussex Neuroscience Seminar Room, CRPC Building 4.03, University of Sussex
Professor Marco Leyton
Department of Psychiatry, Faculty of Medicine,
McGill University, Quebec, Canada
Altered dopamine neurotransmission has long been implicated in the susceptibility to and development of addictions. However, our understanding of how this occurs remains poor, particularly in humans.
Today’s presentation will summarise recent developments using functional neuroimaging and methods for manipulating dopamine transmission.
These studies suggest that, in healthy humans, compulsively abused drugs across multiple pharmacological classes increase extracellular dopamine levels in the striatum. These effects are closely related to the ability of reward-related cues to elicit and sustain approach and desire, weakly related to positive mood tone, and related to euphoria only tenuously if at all.
Individual differences in the magnitude of these dopamine responses have been associated with differences in personality traits, cortical thickness, serotonergic tone, autoreceptor mediated inhibitory feedback, and past drug exposure. Following repeated drug use, the dopamine responses can become progressively larger (sensitised) and conditioned to environmental cues. Both of these effects are seen first within the ventral limbic striatum, and then, as drug exposure increases, in the dorsolateral striatum.
Finally, impulsive individuals at risk for addictions exhibit altered drug-induced dopamine responses. Both increases and decreases have been observed, potentially related to the presence vs. absence of drug related cues. Together, these studies replicate and extend features identified in animal models, and raise the possibility that one biological vulnerability trait for addiction is susceptibility to labile dopaminergic and appetitive responses to reward-related cues.