Discussing criteria for addictive disorders considered in the DSM-5

2.4.1. Is splitting the body and the mind the right way to distinguish between SUDs and non-SUDs?

An appealing fact when analyzing the new DSM-5 category (American Psychiatric Association, 2013) for addictive disorders is that SUD criteria are mainly oriented toward the product (i.e., the drug) and its physical effects on the excessive repetitive user. On the other hand, for BAs, specific criteria are more based on the individual and the individual’s cognitions (i.e., the item often preoccupied in GD and IGD), emotional coping (i.e., the items often gambles when feeling distressed; and uses gaming to escape or relieve a negative mood), and interpersonal interaction in relation to the problematic behavior (i.e., the items deceived family members, therapists, or others regarding the amount of Internet gaming; and lies to conceal the extent of involvement with gambling).

It seems that for GD and IGD, the manual (American Psychiatric Association, 2013) considers emotional and cognitive processes but not for SUDs, though excessive substance users often use the drug to cope with emotional states (Deleuze et al., 2015; Selby, Anestis, &

11 Joiner, 2008), are preoccupied by their past or future drug consumption (i.e., preoccupation/anticipation phase of the addiction cycle)(Koob & Le Moal, 2001), and tend to minimize the extent and risks of their consumption (described as an impaired insight or reduced self-awareness)(Moeller et al., 2014). Furthermore, data accumulates on neural correlates of these psychological processes involved in SUDs (Koob & Le Moal, 2001;

Moeller, et al., 2014).

This difference in diagnostic criteria for addictive disorders (i.e., a product-oriented approach for SUDs and an individual-oriented approach for BAs) suggests that the presence of a drug in SUDs places the determinism of the addictive disorder at a biological response level, whereas for BAs such as GD and IGD, the determinism is considered at a mixed level: psychological (e.g., coping, chasing losses, preoccupation) and biological (e.g. tolerance and withdrawal symptoms). This issue has to be addressed further in light of recent conceptual changes in the addiction field.

2.4.2. What is really specific to SUDs?

For SUDs, specific criteria chosen in the DSM-5 consisted of (1) high engagement in drug seeking and consuming or recovering from substance effects, (2) interference with obligations, and (3) drug craving. The distinction made in the DSM-5 between SUDs and BAs based on these criteria is a matter of question.

Considering the high engagement criterion, first, problematic gamblers and gamers spend a large amount of time engaged in seeking opportunities to gamble or to game and in developing strategies and techniques to win money or to reach higher game levels (Billieux et al., 2015; Yau & Potenza, 2015). This reward seeking could be seen as equivalent to drug seeking. Nevertheless, the DSM-5 considered this kind of high engagement for GD but included it as a preoccupation item. Second, excessive gamblers and gamers spend much time

12 gambling or gaming, often at the expense of other activities (Billieux, et al., 2015; Yau &

Potenza, 2015), and this could be comparable to high engagement in drug consumption.

Finally, they are probably highly engaged in trying to recover from the negative consequences of gambling or gaming (e.g., financial losses, sleep deprivation, and extreme emotional involvement).

It is also hard to admit interference with obligations as a distinctive criterion between SUDs and BAs because problematic gambling and gaming sessions also often interfere with professional, academic, and social obligations (Billieux, et al., 2015; Yau & Potenza, 2015).

Finally, problematic gamblers and gamers are often driven by craving (Yau & Potenza, 2015) to gamble or to game, which is probably related to intense memories of past gambling and gaming experiences or driven by cue-induced urges as for SUDs (Noori, Cosa Linan, &

Spanagel, 2016).

2.4.3. What is really specific to BAs?

In DSM-5 diagnostic criteria, motivational factors are considered for GD (chasing and coping) and IGD (escaping and coping), but not for SUDs. This lack in the SUD clinical diagnosis seems to be in line with the proposal by Rehm et al. (Rehm et al., 2013) for “heavy substance use over time ” being the unique condition required to define SUDs.” This is problematic because defining addictive behaviors by the amount of excessive and continuous drug use and related harms, in addition to being imprecise, neglects the internal driving force of addiction and puts aside the individual’s cognitive and emotional experiences (Saunders, 2013). These individual experiences are associated with drug consumption and excessive gambling and gaming (Deleuze, et al., 2015), and excessive use and involvement has been associated with addiction symptoms and coping strategies (Deleuze, et al., 2015). These

13 potential positive and negative reinforcing factors could explain the maintenance and relapses of problematic use and constitute a psychotherapeutic target.

Moreover, the main neural systems involved in these motivational processes are the dopaminergic system for reward seeking and the serotoninergic system for emotional regulation for both SUDs and non-SUDs (Potenza, 2006).

The reward pathway is the cornerstone of the hypothesized involvement of the dopaminergic system in addictive disorders. The mechanism is that drugs target the same brain circuitry that mediates natural rewards in a more intense way. Experimental designs showed, for example, a 150% to 300% increase in dopamine in the nucleus accumbens after heroin injection (Wise, Leone, Rivest, & Leeb, 1995) versus a 37% increase for food consumption (Hernandez &

Hoebel, 1988) and a 50% increase for copulatory behaviors (Pfaus et al., 1990). Moreover, when a choice was given between drug and food, a weak proportion of rats preferred the drug to the natural reward (Carroll, Lac, & Nygaard, 1989), supporting the individual vulnerability factor in the development of preference for potential addictive rewards over natural rewards (Cantin et al., 2010).

2.4.4. Why exclude continuation despite adverse consequences of GD criteria?

A recent paper (Clark, 2014) discusses whether BAs involve sufficient rewarding conditions to lead to addiction to the same extent as SUDs if they lack the potent rewarding exogenous drug intake. Response pathways seem to reside in learning biases (e.g., preeminence of positive reward anticipation even after experiencing repetitive negative outcomes), inner vulnerability factors (such as impulsivity traits), and qualitative (e.g., the potency of reinforcing factors associated with the behavior) rather than quantitative rewarding power (Clark, 2014). These pathways could explain the decision-making bias that leads to the pursuit of excessive drug intake or behaviors despite adverse consequences. A multifaceted

14 impulsivity trait, for example, has been found to be shared by those with GD and SUDs when compared with healthy controls (Clark, 2014). Disordered gamblers have indeed been found to share risky decision-making with alcohol-dependent subjects (Clark, 2014). They also share deficits in response inhibition and the mood-related facet of impulsivity (i.e., urgency) with cocaine-dependent subjects (Clark, 2014). Insensitivity to choice feedback is shared by GD and nicotine-dependent subjects (Clark, 2014). Differences in impulsivity facets have been found between SUDs and GD: alcohol-dependent patients present additional deficits in impulsive action (i.e., response inhibition) and those with GD show greater deficits in impulsive choice (i.e., delay discounting) than do cocaine-dependent subjects (Clark, 2014).

Moreover, high-craving gambling cues have been found to reverse the usual subjective value coding pattern and to be conducive to more impulsive choice (Miedl, Buchel, & Peters, 2014).

IGD have also been found to be linked to high impulsivity traits and to impaired impulsive choices and actions (Robbins & Clark, 2015). The distinction made in the DSM-5 between SUDs and IGD on the one hand and GD on the other regarding these criteria (i.e., continuation despite negative consequences considered for the first two disorders and not considered for the last disorder), however, remains incomprehensible.

2.4.5. What are the specific criteria for GD?

The main illustration of learning biases present in those with GD, which lead to erroneous and risky decision-decision making, is the solid conviction of future wins despite experiencing repeated losses. Gambling is mainly based on hazard-driven monetary rewards.

The human brain tends to erroneously process information under probabilistic conditions.

When estimating their chances of winning, disordered gamblers seem to have stronger beliefs in their irrelevant perceptions than do non-disordered gamblers (Ladouceur et al., 2004). Such cognitive distortions are called gambler’s fallacy and illusion of control. The near-miss effect, for example, is the perception of close wins that the brain processes as if they were wins, even

15 when objective losses are experienced (e.g., an outcome of two of three fruits in a slot machine) (Clark, 2014). This cognitive distortion can partly explain the failure of the learning process (i.e., absence of extinction of gambling behavior despite repetitive loss experiences) in disordered gamblers. These fallacies have been investigated, through previously reviewed and discussed neuropsychological and neuro-functional designs (Achab, Nicolier, Khazaal, Zullino, & Haffen, 2012), as being responsible for the development, maintenance, and severity of GD. The potent incentive nature of gambling, added to its physiologically arousing intensity, can lead a minority of gamblers to lose control and engage in problematic repeated behavior. They are driven by unsuccessful attempts to apply learning rules (i.e., the more you train, the more you become skilled) to a random activity.

Seeking the “chance” to make an “easy big win” could represent the addictive ingredient (i.e., comparable to neurobiological drug effects) in GD. Accordingly, chasing losses is a specific criterion recently introduced in the DSM-5 to diagnose GD as an addictive disorder.

2.4.6. What are the specific criteria for IGD?

Surprisingly, no specific criterion was considered for potential IGD as part of the addiction spectrum. Video games offer a wide range of rewarding conditions (e.g., skill development, advancement, social recognition, competition) distinct from drugs and from gambling (Billieux et al., 2013).

Reinforcing properties are in some ways similar to gambling reward through variable-ratio schedules (e.g., repetitive actions required to kill monsters under uncertainty for many parameters, such as the moment when the outcome will be achieved, and the weak winning probability of a particularly rare item) (Thorens, Wullschleger, Khan, Achab, & Zullino, 2012).

16 Salient stimulus triggering of a reward in the brain system in online games could be represented by reinforcing a social interaction that is made possible, anonymous, immediate, and endless by the Internet. Communication, cooperation, acceptance, humor, hierarchy, comparison, and competition opportunities are present in these games (Thorens, et al., 2012).

The kinetics of online games causes the reinforcing factors to be delivered in an addictive scheme. Indeed, salient stimulus presentation follows operant conditioning rules, delivering immediate and continuous rewards (e.g., skills, levels, virtual money) during the character’s advancement (Thorens, et al., 2012). Highly incentive rewards (e.g., rare equipment or access to highly competitive game scenes) are delivered by intermittent reinforcement (Thorens, et al., 2012). High game accessibility and interactivity through Internet technology is facilitating factor for an addictive pattern of use. For a detailed description of game conditioning mechanisms, see the paper by Thorens et al. (Thorens, et al., 2012).

Furthermore, online video games seem to be more likely to lead to problematic use than offline video games (M.D. Griffiths & Meredith, 2009). The specific addictive component (comparable to the product in SUDs) of such games may be delivered through the addictive vector, the Internet.

The temporality of these online games is characterized by their never-ending development, with regular exciting new challenges, appealing graphic environments, and potent and rare skills. Moreover, the Internet has created persistent games that continue to exist and develop even when there are no gamers interacting with them (Bartle, 2003). This phenomenon could partly explain why problematic online gamers are often preoccupied by what is going on in-game even when they cannot connect to the in-game. This could be an addictive component of these games, leading the gamer to connect to verify whether any changes have occurred during his or her absence (e.g., other gamers’ advancement, the rank evolution of the gamer’s character). This could also be a maintaining factor of problematic use and an obstacle against

17 remission for addicted gamers. Preoccupation is an item that has been introduced in the proposed criteria for IGD in the DSM-5. Nonetheless, from our point of view, being triggered by thoughts related to game persistence should be an additional specific criterion within IGD diagnostic criteria.

In summary, BAs (i.e., GD and IGD) have contributed to a great extent to a deep change in the conceptualization of the addictive spectrum. A new addiction category (i.e., “Non-Substance-Related Disorders”) has been born (in the classification of mental disorders in the DSM-5) (American Psychiatric Association, 2013). Disorders deserving to be part of it must correspond to strong and valid evidence in favor of their belonging to mental disorders and addictive disorders.

After an overview of the magnitude of the phenomenon and a discussion of conceptual changes and underlying neurobiological and psychological arguments for GD and IGD, the next chapters present our scientific findings (original research and systematic review papers) on the features of GD and IGD (i.e., psychopathological, assessment, and therapeutic) in the spectrum of addictive disorders . Five recently published papers are provided in-extenso at the end of the manuscript (in an appendix). Within the manuscript, they will be presented through a brief introductory paragraph that highlights several aspects. Studying GD and IGD features within the addictive spectrum

In addition to the conceptual evolution of the addictive spectrum, we were interested in our research in studying the differences and similarities between SUDs and BAs and in extracting the specificities of GD and IGD that could have clinical implications.