The Translation of Substance Dependence Criteria to Food-Related Behaviors: Different Views and Interpretations

In recent years, a food addiction model of obesity and overeating is gaining more and more popularity. A remarkable increase of the number of publications containing the topic food addiction has been observed since 2009 (Gearhardt et al., 2011). The concept of food addiction proposes that there are similarities – both neurobiological and behavioral – between obesity (or overeating) and substance dependence and suggests that hyperpalatable foods could have an addiction potential (Gearhardt et al., 2011). One of the most highlighted arguments is that DSM-IV substance dependence criteria also apply to overeating provided they are modified with references to binge eating (Cassin and von Ranson, 2007). A reward deficiency syndrome is also considered reflected by a downregulation of striatal D2-receptor availability and concurrent hypersensitivity to palatable food-cues in obese individuals (Kenny, 2011). Ziauddeen et al. (2012) recently presented a critical evaluation of this food addiction model of obesity and overeating. Some key conclusions drawn in this article are that a vast majority of obese individuals would not show a convincing behavioral or neurobiological profile that resembles addiction and that the evidence for an overlap with addiction would be inconsistent and weak even when the food addiction model would be refined to obese individuals with binge eating disorder (BED). Specifically, the authors conclude that “food addiction may prevail in non-obese and not-yet-obese individuals” and that “obesity, particularly when assessed solely cross-sectionally by body-mass index, will be an unsatisfactory phenotype for food addiction” (Ziauddeen et al., 2012, p. 281). In our opinion, Ziauddeen et al. (2012) correctly infer that not all obese individuals are food addicted and that food addiction does rather relate to binge eating behaviors, but they miss the fact that most researchers in this area would agree with this idea. For example, many researchers do mention that food addiction is not restricted to obesity, but also occurs in normal-weight samples, e.g., in patients with bulimia nervosa in particular (e.g., Davis and Carter, 2009; Gearhardt et al., 2009a; Broft et al., 2011; Meule, 2011; Speranza et al., 2012; Umberg et al., 2012). Furthermore, recent studies using the Yale Food Addiction Scale (YFAS) show that only a subset of obese individuals receive a “diagnosis” of food addiction (between 25 and 42%; Davis et al., 2011; Meule et al., in press a,b) supporting the notion of the authors of a better behavioral profiling of investigations (p. 284). Nonetheless, obese individuals are well-suited for research on food addiction because symptomatology is much more prevalent as compared to non-obese samples (Meule, 2011). Another conclusion of the authors is that “the DSM-IV criteria for substance dependence translate poorly to food-related behaviors” (p. 281). The proposed food addiction equivalents of substance dependence criteria presented by the authors are based on articles by Volkow and O’Brien (2007) and Gearhardt et al. (2009a). We argue that those criteria require further examination. Firstly, Ziauddeen et al. (2012) acknowledge that some criteria are easily applied to eating behavior, those are (1) a persistent desire or unsuccessful attempts to cut down (2) larger amounts consumed than intended and (3) continued use despite physical or psychological problems. They do also suggest, that these criteria require “the application of severity and impairment thresholds to be meaningful” (p. 280), although such thresholds do not exist for substance dependence. Dieting attempts, occasional overeating, and unhealthy eating despite problems apply to many people regardless of food addiction symptomatology that is why, as in substance dependence, not a single criterion suffices to receive the “diagnosis” food addiction. Specific severity thresholds may be difficult to establish because of a lack of a clear addictive agent associated with food addiction. However, the only currently available measure for establishing a diagnosis of food addiction, the YFAS, includes items for the assessment of distress or a clinically significant impairment because of eating and food addiction is only diagnosed when this criterion is met (Gearhardt et al., 2009b; Meule et al., in press b). Secondly, the authors argue that the criteria of tolerance and neglecting or abandoning important activities in favor of substance-related activities have no convincing equivalents in relation to eating behavior. They define tolerance such that increasing amounts of food are required to reach satiety and that important activities are given up due to fear of rejection because of obesity. These definitions, however, differ from the definitions used in current research. For instance, the YFAS defines tolerance such that increasing amounts of food are necessary to reduce negative emotions or increase pleasure or that the same amount of food does no longer enhance mood (Gearhardt et al., 2009b; Meule et al., in press b). With regard to neglecting important activities, the authors propose that “a strict equivalent would require The translation of substance dependence criteria to food-related behaviors: different views and interpretations