Summary of evidence: To take each of the questions in turn, The Gamblers Consumer Forum supports the introduction of the statutory levy, provided it is used to support a balanced and evidence-based conversation around addiction. We outline in our answer why the anti-gambling sentiments that have, thus far, occupied so much of the debate regarding gambling regulation, need to be curbed in order that we can base our education of the public and treat those addicted on a scientific, objective analysis of harm.
Regarding the second question, we outline why we believe the most significant gap in the White Paper is the Government’s lack of understanding when it comes to the nature of addiction. We use evidence from clinical experts and studies based in neuroscience and psychiatry to illustrate the genetic link to addictive tendencies, explaining why the harm does not lie with the product, and that there is a vast cognitive difference between an addict and a healthy bettor, the latter of whom does not need to be subject to any measures at all.
In answering the last question, we explain why we believe the introduction of affordability checks are unnecessary, illiberal, and impractical. We evidence this statement by drawing on the example of Ireland refusing to adopt any affordability criteria, the evidence that the black market is indeed growing, and the fact that credit checks and scores cannot provide an accurate depiction of someone’s financial position. We strongly argue against affordability checks of any description and believe that they should be removed from all legislation, on the basis of their obvious impracticality, and their potential damage to industries such as the horseracing industry, who are the lifeblood of many local economies and rely heavily on betting turnover.
About the Gamblers Consumer Forum: The Gamblers Consumer Forum are an organisation that supports the ordinary gambler, the addict, the small independent bookmaker, and the industries that gambling supports. We are submitting evidence to this inquiry because we believe that the voice of ordinary gamblers have been silenced by a prolific anti-gambling lobby who have thrived on making the issue of addiction a political one rather than what it is, a clinical one. We use this evidence as an opportunity to support those we seek to represent by explaining why we believe the White Paper is flawed, and why the Government should put the mitigation of addiction harm into the hands of the clinicians, not the politicians.
1. What are the most welcome proposals in the Gambling White Paper?
The Gamblers Consumer Forum welcome the introduction of the statutory levy, provided it is used for pioneering, clinical research into addiction and to educate people in the signs and symptoms of addiction. We would object to the statutory levy being used for yet more anti-gambling research, typically authored by non-clinicians, that suggest gambling harm indiscriminately affects everyone, and is predicated on the notion that everyone is one step away from addiction. This doctrine goes against what we know about addiction as a whole; addiction is a specific condition in individuals, rooted in deficiencies of key neurotransmitters and regions within the brain. This succinctly explains why we do not all have an addiction of some form, despite the mass availability of addictive agents. If exposure to addictive agents was the cause of addiction, as some research tries to suggest, all adults should, in theory, to addicted to something.
We agree it is important that young people use school as an opportunity to learn how to keep a healthy mind, in the same way they learn how to preserve their physical health. However, as with all teaching practices, this must not be hijacked by the dogmatic approaches we have seen in the debate surround gambling regulation thus far, and must be a well-rounded and balanced conversation, informed by evidence-based science and not ideology.
Addiction should be taught as a whole entity that can take many variations, rather than focussing on specific forms, most of which have varied and often unsubstantiated definitions coined by activist groups rather than clinical professionals. Segmenting off addictions is the wrong approach for several reasons, chief among them are 1) it makes it harder to identify various addictions, or multiple addictions, if they all have different characteristics ie it is not widely considered that spending a high amount of money on alcohol is a sign of alcoholism, yet high expenditure is considered a red flag for gambling harm, despite the fact this is more than likely an indicator of income rather than an indicator of harm, and 2) it too easily conflates other factors by creating endless lists of markers for individual conditions; the Gambling Commission defines one of its 23 harm markers as an increase in spend around payday, yet this is a perfectly normal, and logical, consumer behaviour, since every employed individual’s disposable income increases on that particular day. Indeed, it is likely that a good number of these harm markers are applicable to most of the population, whether they gamble or not. Addiction, whatever its form, is the compulsive and uncontrollable desire to do something that is harming you, and it is that trait that people, particularly young people, should learn to identify in themselves in order to recognise whether they may be an addict.
It is also important to acknowledge in our education of gambling harm that gambling in itself is not a shameful act – it is a perfectly normal and natural activity; the desire to want to predict the outcome of an event and be part of the win is hardwired evolutionarily in the human brain. It is derived from the same part of our brains that compelled us to guess what raindrop will fall down the window faster as children. Whilst it is true that some individuals are harmed by this particular cognitive ability, this is true of nearly almost every recreational activity. The total elimination of harm is simply an impossible goal.
As well as representing the ordinary gambler – whether they place a bet every day or participate in their Grand National office sweepstake once a year – the GCF are proud to also represent the addict, and seek to ensure they receive the best clinical treatment, backed and advised upon by qualified professionals, as with all other addictions. We firmly believe the very last thing addicts need is to be lumped together with healthy recreational bettors under a blanket of arbitrary regulation. Clinical treatment is clearly the vastly more effective measure than providing a bank statement or blocking the viewing of advertising. The latter are merely substitute policies for the real solution.
2. Are there any significant gaps in the Government’s reforms?
Addicts and the healthy gambler
The Gamblers Consumer Forum believe the phrasing of this question only serves to highlight the Government’s willingness to consider even more draconian, restrictive, and disproportionate regulation, when it’s clear the White Paper in its current form will already have a significant impact on 1) the perfectly democratic right for individuals to spend their money as they see fit, 2) the gambling industry itself, most notably the hundreds of independent bookmakers that serve as employers and tax revenue providers, and 3) industries such as the British horse racing industry, which not only hosts some of the most beloved races in the world, but is also a part of this country’s rich sporting heritage. We fear the Government, when these measures have no impact on the rate of gambling addicts, or will resultantly see an increase in the black market, will introduce yet more regulation.
Before this White Paper has even left the consultation stage, what was hailed the revolutionary overhaul of the 2005 Gambling Act, there are those who are still seeking more, moving towards their end goal to ban gambling. If these individuals and activist groups continue to be the main driving force for policy, these consultations will be nothing but confirmations, and will only serve as talking shops for, not whether these proposals have any modicum of practicality in a real-world setting, but whether the Government’s response is still sufficient enough. Gambling is now at the stage where it is more heavily regulated than smoking, a practice we can all agree is indiscriminately harmful, killing 76,000 people in the UK a year – you don’t have to pass a health check to purchase a packet of cigarettes, but you might have to pass a credit check to place a bet, even if the act of gambling causes no harm to you at all.
The only significant gap in the Government’s reforms is a lack of understanding of the nature of addiction. Understanding addiction is the bedrock of this legislation, because it is what allows you to identify who requires the help the Government are seeking to provide – arguably the very purpose of these reforms. The reason why this lack of understanding of addiction is so important for the overall debate is because you cannot recognise those who do not need protect, help, and measures, until you are able to correct recognise those that actually require the protection, help, and measures. Regrettably, the White Paper is predicated on the idea that everyone needs some form of protection, and that is why these proposals will remain deeply flawed until the Government acknowledges that while there are some individuals who need help in identifying, treating, and managing their addiction, the vast, vast majority of individuals need no help whatsoever. Therefore, much of this legalisation, namely affordability checks, is, to them, entirely unnecessary, disproportionate, and meaningless. To understand the nature of addiction is to understand that 99.6% of gamblers should be left to enjoy their hobby as free and independent adults.
Separating out addicts from healthy gamblers requires a willingness from the Government to recognise that addicts cognitively operate in an entirely different way to that of a healthy bettor, and that we need to recognise them as two distinct groups of people that do not need to be subject to the same measures, in a similar manner to the way we recognise children with dyslexia have different needs to the rest of their peers. This is not disparaging; indeed, it is the best way to direct and target resources to those most in need. The White Paper arguably does the opposite of this – its application is general, rather than specifically identifying, based on the sole unscientific notion that because “everyone has a casino in their pocket”, everyone is at equal risk of becoming addicted. We all have the same ability to purchase alcohol, fatty foods, cigarettes, and pornography, but that doesn’t mean we all exploit them equally.
The ’problem gambler’ myth
We believe the term ‘problem gambler’, which is so deeply entrenched in the Government’s view of gambling, is based entirely around this ideology, rather than the evidence we have on addiction as a cognitive condition. Indeed, the anti-gambling lobby, who coined this particular phrase, can’t even decide among themselves what the figure of ‘problem gamblers’ is, having left the definition deliberately vague in order to exaggerate the number of individuals who can be said to be adversely affected by gambling. Indeed, for other addictions, there is no comparable terminology – there is no such thing as ‘problem pornography watchers’ or ‘problem heroin users’ – they are simply addicts. To use the phrase ‘problem gambler’ is to falsely conflate the problem with gambling, rather than the problem lying with the cognitive operation of the addict. Indeed, if the problem was solely gambling – that to ban the gambling product tomorrow would ‘cure’ the 0.2% of those who suffer from addiction – it wouldn’t be the case that many addicts are found to have multiple addictions. Clearly, the problem does not lie with the product. This is confirmed by Staiger, P. K et al (2013) who found that over 30% of those seeking treatment for alcoholism also presented with drug addiction. Furthermore, Slutske, W et al (2000) found that between 45% and 63% of those suffering from pathological gambling also report a history of alcohol abuse or dependence. This provides the reason why it is incorrect to attempt to individualise and separate addictions, since they are all so deeply united by the common thread of compulsive behaviour, and often, as the multiple addiction figures illustrates, exist together. To seek to prevent gambling in addicts through measures such as affordability checks will not prevent addiction. It will either push addicts to a black market where they can continue their addiction off the radar, or push them towards a substitute addiction, if indeed they do not already have one.
We should instead by collating our knowledge from other addictions to help identify, treat, and manage gambling addictions, just as we do with other diseases that have different variations, such as different forms of cancer. We should also use our knowledge of past regulatory errors to better inform our current ones. Smoking is falling in every developed country in the world, in places where outdoor advertising is unrestricted, such as in Germany, and in locations with heavy restrictions on commercial freedoms, such as the United Kingdom. What hasn’t reduced, however, is nicotine use. And so, this regulation has only served to disguise the problem, and has merely created a shift from one addictive agent to another. What is the proposal for gambling addicts who shift their addictions to another agent? The evidence from smoking vs nicotine use and the fact gambling addicts present with other addictions suggests this is likely to be the case.
In an interview with one of our founding members, Dr Robert Lefever, himself a recovering addict and a pioneering addiction recovery specialist who opened the first addiction rehabilitation clinic in the UK, suggests the Government have ignored the fundamental nature of addiction. He estimates that 1/6 of the population has an addictive nature, be it alcohol, gambling, sex, substance abuse, food, or shopping. Contrastively, 5/6 of the population have no issue across the board with regards to addiction whatsoever. He believes two core things:
- That addiction is black and white – either you have addictive tendencies or you do not. The GCF are in total agreement with this concept, given there is no evidence that addiction presents as a continuum. Is there a record of clinical diagnoses by addiction specialists under an umbrella term of ‘half-way addict’? Or ‘nearly an addict’? Perhaps ‘minor addict’ vs ‘severe addict?’ Or is are their simply diagnoses of those who have an addiction?
- He believes the problem is genetic – that addictions are clustered by deficiencies in key neurotransmitters: dopamine, as with gambling, serotonin, and norepinephrine, and that those who have multiple addictions are likely to be derived from the same cluster group. Again, the GCF would agree with this also, as it again explains why certain individuals choose to treat hardship with addictive agents, where the vast majority of adults, most of whom will have all experienced some kind of hardship in their lives, will not.
This also highlights why the Government is misguided in their approach to gambling advertising. Specifically, the GCF are sceptical as to how advertising algorithms will be programmed to prevent a ‘vulnerable person’ from viewing gambling advertising, given this is a highly subjective term, but more generally, it helps perpetuate the myth that human beings have no free will – that the only thing that motivates our behaviour are the things that are marketed to us. Again, if exposure to advertising was responsible for addiction, why are we not addicted to an addictive agent, given how prevalent and sophisticatedly targeted advertising is in the modern era? Furthermore, if you were able to acquire addiction from free bet promotions on advertising, why isn’t every regular gambler who uses these facilities addicted? The motivation behind these measures do not explain the existence of the 99.8% that gamble without issue.
The science-backed approach
This is the research that informs the scientific argument of the Gamblers Consumer Forum, one we believe the Government should also consider.
When a pathological gambler wins a bet, their brain is flooded with dopamine, as with all gamblers – they feel elation – but critically, for a pathological gambler, when they lose a bet, they need the dopamine hit again. The pathological gambler will then typically place a high-stake, high-reward bet to compensate for the lack of dopamine in their limbic system. Overtime, their brain’s circuitry system builds up tolerance to an excess of dopamine, and so more dopamine is required to generate a ‘high’. This is all as a result of the way dopamine functions in the brain of an addict.
The brain strives to maintain balance, but altering its neural pathways means a false equilibrium is created. Association networks in the brain of the addict, like the basal ganglia, actively work to increase the efficacy of the dopamine signal when a ‘low’ occurs to try and maintain a new balance with an inflated ‘high’. Floresco (2015) found that when an action is followed by an increase in dopamine activity, the basal ganglia circuit is altered in a way that makes the same response easier to evoke when similar situations arise in the future.
The reason for the alteration is circuitry is derived from the regulation of dopamine, which is genetic. Indeed, the National Institute on Drug Abuse estimate genetic factors are 40-60% responsible for addiction.
The COMT gene (the gene that provides instructions for making an enzyme called catechol-o-methytransferase) is responsible for the regulation of dopamine in the brain, and is embedded our in 22nd chromosome. There are two alleles (or variations) to that COMT gene: met, and val. Research has uncovered that those who possess the met allele have a reduced capacity, compared to those with the val allele, to remove dopamine from the brain ie the brain takes a more sustained dopamine hit.
Verhagen et al (2010) estimates that 20-30% of white Europeans carry the met allele. met carriers show more reward sensitivity if they win something, or if they experience high stress. They have higher attention to reward and gain (Bilder et al, 2004), and these characteristics influence their decision making in the prefrontal cortex. Carriers of met are found to, in some studies up to 25% have more extracelluar dopamine levels in their brain compared to val carriers, so in essence, when triggered, met carriers have significantly more dopamine in their limbic system that majority of the population. Because this affects dopamine neurotransmission in the nucleus accumbens (structures involved in mediating motivational processes), pathological gamblers ‘want’ to gamble, even if they don’t actually derive pleasure from it.
Turning to the contribution of environmental factors, we know that certain individuals are genetically predisposed to stress, and we also know that stress can increase your dopamine levels (Calipari et al, 2021), leading to an increased tolerance. By examining the alleles present, researchers have found a link between stress and pathological gambling.
The short allele of the serotonin transporter (5-httlpr) is associated with a heightened response to environmental stimuli and an acute awareness of stressful situations. The short allele was found by Perez De Castro et al (1999) to be significantly more frequent in male pathological gamblers. We also see these in the met allele of the COMT gene – a sensitivity to reward and gain, and susceptibility to stress.
People exposed to psychological adversity, particularly in childhood, have an impaired function of their norepinephrine neurotransmitter (Ibanez et al, 2003) – meaning the neurotransmitters and hormones related to stress are dysfunctional. This was found to be higher in pathological gamblers. However, not everyone who experiences stress then becomes a pathological gambler. This therefore suggests that pathological gamblers are both exposed to stress and have an inhibited genetic predisposition to be able to deal with that stress. Further compounding this idea, Comings et al (1996) found carriers of the Taq1a allele have reduced D2 receptor binding, meaning they have a high pain threshold. This creates the perfect genetic storm for an addict to function: an insatiable desire to win, combined with a lack a pain when experiencing a loss.
The GCF have yet to see an discussion involving clinical and neurological research such as this. What we have seen in abundance in research in the social and economic domain. What we find most worrying is that this is not one study in isolation – study after study, just from the ones cited in this document, show a genetic link with gambling addiction. This is why the GCF are calling for a panel of objective, qualified clinicians, who are experts in addiction recovery, to advise the Govt in how best to treat addicts, replacing the current set up of anti-gambling sociologists whose starting point is that gambling is a social issue that can be caught through exposure.
The GCF are concerned this is research is largely ignored because the anti-gambling lobby, who have so much power and influence over the debate on gambling regulation, find it inconvenient to their narrative. It is staggering to witness a discussion about a clinical condition with so little clinical research and evidence. Going forward, this is something the Government urgently need to address, as this significant gap is what decides whether addicts will get the support that they need, and the fate of those who do not need the support – whether they are able to exercise their perfectly legal right to place a bet and continue to support the industries that are the lifeblood of many local economies.
3. What are the potential barriers to the Government and Gambling Commission delivering the White Paper’s main measures by summer 2024, the Government’s stated aim?
We believe there are several barriers to the Government and Gambling Commission achieving their aims. This would be in stark contrast to the lack of barriers to the Commission in delivering the White Paper. We believe that if the White Paper had been conducted as a Royal Commission, it would have been less susceptible to prohibitionist lobbying and the ideological views of certain Ministers. It would also have had the opportunity to see the methodological failings of the evidence submitted.
In terms of barriers to the White Paper’s main measures, the Gamblers Consumer Forum believe affordability checks are wholly impractical and illiberal – they infantilise a generation of adults who are effectively being told they are unable to manage their own finances, but above all, plainly and simply, they will not work in a real-world setting.
From an addiction point of view, they do not do anything to address or treat the condition, they merely attempt to temporarily halt it by blocking the ability to place a bet in the regulated market. This, naturally, has unintended consequences. According to a survey conducted by YouGov on behalf of the Betting and Gambling Council, 79% of bettors believed it would result in more people going to the black market, and they were right – black market gambling site visits trebled during the World Cup. That is an absolutely staggering figure. Even more staggering is the fact that anti-gambling activists appear very concerned by a 0.2% gambling addiction rate, but they consider what they call a ‘parallel market’ of 1% to be “low”, despite its rise.
In terms of credit checks, we believe these are being manipulated from their proper usage, and as such will produce inaccurate results. A credit check does not provide an accurate financial analysis of the very nuanced financial position of each individual. After all, a person earning £40,000 in London with several children will have a very different disposal income to someone earning the same living in the North of the country without a family. Moreover, a credit check’s purpose is to ensure the likelihood of borrowed money being paid back, not as a sign off for one to spend their own money.
We also believe affordability checks massively disadvantage those who are self-employed, retired, or are concerned about their data privacy. This extends to those whose bank does not facilitate open banking, another way of estimating income and expenditure by decoding transactions. In other words, the infrastructure is just not there to support affordability checks and open banking, making the idea of frictionless regulations near impossible to achieve. The Irish Government have recognised this issue and have no plans to introduce affordability criteria.
Operators have privately reported that when they request documents, 80% of users decide not to provide them. The route of those individuals is either to stop betting altogether, or to divert to the black market. Indeed, the Government may see a repeat of the rush to Gibraltar as seen in the late 90s in a response to betting duty, with users registering in the Republic of Ireland under the CTA to avoid friction and checks. This would result in both a loss to the Treasury and the betting levy as a result of the tens of thousands of gamblers who will get caught up in the criteria as currently set out for when credit checks are instigated. This is why the GCF will be calling for the creation of a Government panel made up of ordinary gamblers, independent bookmakers, and sporting industry representatives to directly influence Government policy concerning gambling, so ensuring there is a balanced conversation based on knowledge and expertise.
The GCF’s fear is that the Government with continue to push ahead with affordability checks, despite evidence this would be a wholly unreliable and disingenuous method. The Gambling Commission themselves cite a University of Liverpool study that shows “that over the course of January 2017, there were 22,080 individuals losing in excess of £1,000 on slots, whilst for non-slots play, there were 10,373 customers losing in excess of £1,000”. Unfortunately, The Gambling Commission then conveniently omits the caveat found in the original report: “The data tell us nothing about these individuals. Some may be sufficiently wealthy that losses of this magnitude are not important to them. Others might have been returning to the operator large wins earned in the preceding month”.
To conclude, the barrier to achieving the Government’s aim are that they are a solution to a problem that does not exist – a world where the vast majority of people who gamble are harmed by it. Affordability checks are tools to please a fantasy of the anti-gambling lobby that cannot ever come to pass: where gambling harm is completely eliminated. What is almost inevitable is that it will reduce levels of gambling overall by non-addicts, deeply harming the industries gambling and betting turnover support, and will likely increase black market activity in addicts. Ultimately the main barrier is this: the belief that preventing gambling activity will prevent gambling addiction. The most likely outcome of this is a movement by addicts to the unregulated market, or a movement by addicts to another addiction, which arguably, actually makes the problem worse.
The Gamblers Consumer Forum.
- Staiger, P; Richardson B; Long C; Carr V; Marlatt G (2013). Overlooked and underestimated? Problematic alcohol use in clients recovering from drug dependence. Deakin University. Journal contribution.
- Slutske WS, Eisen S, True WR, Lyons MJ, Goldberg J, Tsuang M. Common Genetic Vulnerability for Pathological Gambling and Alcohol Dependence in Men. Arch Gen Psychiatry. 2000;57(7):666–673.
- Who.int [internet, accessed 14th April 2023]
- Smoke Free World [internet, accessed 5th May 2023]
- Spotify [internet, 2nd May 2023]
- Substance Abuse and Mental Health Services Administration (US); Office of the Surgeon General (US). Facing Addiction in America: The Surgeon General’s Report on Alcohol, Drugs, and Health [Internet]. Washington (DC): US Department of Health and Human Services; 2016 Nov. Chapter 2, The Neurobiology of Substance Use, Misuse, and Addiction.
- Floresco SB (2015) The nucleus accumbens: an interface between cognition, emotion, and action. Annu Rev Psychology. 66. 25-52.
- 2020, July 13. Drug Misuse and Addiction.
- Bonetti, S.E.P. Bruzzone, N.A. Sedghi, N.T. Haumann, T. Paunio, K. Kantojärvi, M. Kliuchko, P. Vuust, E. Brattico, (2021) Brain predictive coding processes are associated to COMT gene Val158Met polymorphism, NeuroImage, Volume 233
- Verhagen M, van der Meij A, van Deurzen PA, Janzing JG, Arias-Vasquez A, Buitelaar JK, et al. (2010) Meta-analysis of the BDNF Val66Met polymorphism in major depressive disorder: effects of gender and ethnicity. Mol Psychiatry. Vol. 15. 260–71.
- Bilder, R., Volavka, J., Lachman, H. et al. (2004) The Catechol-O-Methyltransferase Polymorphism: Relations to the Tonic–Phasic Dopamine Hypothesis and Neuropsychiatric Phenotypes. Neuropsychopharmacol. Vol 29, 1943–196.
- Yavich L, Forsberg MM, Karayiorgou M, Gogos JA, Männistö PT. (2007) Site-specific role of catechol-O-methyltransferase in dopamine overflow within prefrontal cortex and dorsal striatum. J Neuroscience ;27(38). 10196-209.
- Dreher JC, Kohn P, Kolachana B, Weinberger DR, Berman KF. (2008) Variation in dopamine genes influences responsivity of the human reward system. Proc Natl Acad Sci U S A. 106(2). 617-22.
- Júlio-Costa A, Antunes A, Lopes-Silva J, Moreira B, Vianna G, Wood G, Carvalho MR, Haase V. (2013) Count on dopamine: influences of COMT polymorphisms on numerical cognition, Frontiers in Psychology, Volume 4.
- Floresco SB. (2015) The nucleus accumbens: an interface between cognition, emotion, and action. Annu Rev Psychol. Vol 66. 25-52.
- Consoli DC, Brady LJ, Bowman AB, Calipari ES, Harrison FE. (2021) Ascorbate deficiency decreases dopamine release in gulo-/- and APP/PSEN1 mice. J Neurochem. 157(3). 656-665.
- de Castro, IP; Ibánez, A; Saiz-Ruiz, J; Fernández-Piqueras, J. (1999) Genetic contribution to pathological gambling: possible association between a functional DNA polymorphism at the serotonin transporter gene (5-HTT) and affected men. Pharmacogenetics 9(3). 397-400.
- Ib´a˜nez A, Blanco C, Perez de Castro I, Fernandez-Piqueras J, S’iaz-Ruiz J. (2003) Genetics of Pathological Gambling. Journal of Gambling Studies. Human Sciences Press, Inc. 19 (1).
- Comings DE, Rosenthal RJ, Lesieur HR, Rugle LJ, Muhleman D, Chiu C, Dietz G, Gade R. (1996) A study of the dopamine D2 receptor gene in pathological gambling. Pharmacogenetics. 6(3). 223-34.
- Betting and Gaming Council [internet, accessed 12th July 2023]
- Mirror.uk [internet, accessed 12th July 2023]
- The Guardian [internet, accessed 12th July 2023]
- Forrest D, McHale I. (2018) Analysis Of Play Among British Online Gamblers On Slots And Other Casino-Style Games, University of Liverpool [internet, accessed 23rd June 2023]
 Staiger, P; Richardson B; Long C; Carr V; Marlatt G (2013). Overlooked and underestimated? Problematic alcohol use in clients recovering from drug dependence. Deakin University. Journal contribution.
 Slutske WS, Eisen S, True WR, Lyons MJ, Goldberg J, Tsuang M. Common Genetic Vulnerability for Pathological Gambling and Alcohol Dependence in Men. Arch Gen Psychiatry. 2000;57(7):666–673.
 Substance Abuse and Mental Health Services Administration (US); Office of the Surgeon General (US). Facing Addiction in America: The Surgeon General’s Report on Alcohol, Drugs, and Health [Internet]. Washington (DC): US Department of Health and Human Services; 2016 Nov. Chapter 2, The Neurobiology of Substance Use, Misuse, and Addiction.
 Floresco SB (2015) The nucleus accumbens: an interface between cognition, emotion, and action. Annu Rev Psychology. 66. 25-52.
 NIDA. 2020, July 13. Drug Misuse and Addiction. Retrieved from https://nida.nih.gov/publications/drugs-brains-behavior-science-addiction/drug-misuse-addiction
 L. Bonetti, S.E.P. Bruzzone, N.A. Sedghi, N.T. Haumann, T. Paunio, K. Kantojärvi, M. Kliuchko, P. Vuust, E. Brattico, (2021) Brain predictive coding processes are associated to COMT gene Val158Met polymorphism, NeuroImage, Volume 233
 Verhagen M, van der Meij A, van Deurzen PA, Janzing JG, Arias-Vasquez A, Buitelaar JK, et al. (2010) Meta-analysis of the BDNF Val66Met polymorphism in major depressive disorder: effects of gender and ethnicity. Mol Psychiatry. Vol. 15. 260–71.
 Bilder, R., Volavka, J., Lachman, H. et al. (2004) The Catechol-O-Methyltransferase Polymorphism: Relations to the Tonic–Phasic Dopamine Hypothesis and Neuropsychiatric Phenotypes. Neuropsychopharmacol. Vol 29, 1943–196.
 Yavich L, Forsberg MM, Karayiorgou M, Gogos JA, Männistö PT. (2007) Site-specific role of catechol-O-methyltransferase in dopamine overflow within prefrontal cortex and dorsal striatum. J Neuroscience ;27(38). 10196-209.
 Dreher JC, Kohn P, Kolachana B, Weinberger DR, Berman KF. (2008) Variation in dopamine genes influences responsivity of the human reward system. Proc Natl Acad Sci U S A. 106(2). 617-22.
 Júlio-Costa A, Antunes A, Lopes-Silva J, Moreira B, Vianna G, Wood G, Carvalho MR, Haase V. (2013) Count on dopamine: influences of COMT polymorphisms on numerical cognition, Frontiers in Psychology, Volume 4.
 Floresco SB. (2015) The nucleus accumbens: an interface between cognition, emotion, and action. Annu Rev Psychol. Vol 66. 25-52.
 Consoli DC, Brady LJ, Bowman AB, Calipari ES, Harrison FE. (2021) Ascorbate deficiency decreases dopamine release in gulo-/- and APP/PSEN1 mice. J Neurochem. 157(3). 656-665.
 de Castro, IP; Ibánez, A; Saiz-Ruiz, J; Fernández-Piqueras, J. (1999) Genetic contribution to pathological gambling: possible association between a functional DNA polymorphism at the serotonin transporter gene (5-HTT) and affected men. Pharmacogenetics 9(3). 397-400.
 Ib´a˜nez A, Blanco C, Perez de Castro I, Fernandez-Piqueras J, S’iaz-Ruiz J. (2003) Genetics of Pathological Gambling. Journal of Gambling Studies. Human Sciences Press, Inc. 19 (1).
 Comings DE, Rosenthal RJ, Lesieur HR, Rugle LJ, Muhleman D, Chiu C, Dietz G, Gade R. (1996) A study of the dopamine D2 receptor gene in pathological gambling. Pharmacogenetics. 6(3). 223-34.
 Forrest D, McHale I. (2018) Analysis Of Play Among British Online Gamblers On Slots And Other Casino-Style Games, University of Liverpool [internet, accessed 23rd June 2023]