Vulnerability to addictive behaviors: the Associational Memory‐Appetitive Systems Relations Model
Authors: Steve Sussman
Journal: World Psychiatry (2025)

The concept of behavioral addictions invites controversy, but is slowly penetrating psychiatric consensus. Any addiction involves five components1: a) existence of appetitive needs and b) repeated attempts at satiation of these needs through ingestion of a substance or engagement in a behavior (appetitive effects), followed at some point by c) preoccupation with obtaining appetitive effects (e.g., craving, tolerance), d) loss of control over time spent engaged in appetitive effect-related behavior (e.g., duration, relapse), and e) undesired or negative consequences (such as failure to meet work, familial and social obligations; suffering physical injury; emotional turmoil) resulting from continued engagement in the behavior2. The fundamental underlying perspective is that addiction involves disruption of appetitive functioning; that is, of behavior directed towards fulfilling specific human psycho-socio-biological needs3. It has been theorized that addictive phenomena operate through appetitive mechanisms involving, in part, a misleading, temporary subjective sense of neurobiological fitness4, 5. This experience may be identified through subjective changes in a) affect (e.g., feelings of joy, or merely improvement of affect), b) level of arousal (e.g., alertness or sedation/calm), or c) cognition (e.g., clarity, enlightenment, or decrease in tempo of stream of thought). One may learn to associate in memory the appetitive need (internal cue) with the contexts (location, time of day, situation) and behavior (e.g., sex, work) that led to its temporary subjective satiation, even though the result may not actually be biologically adaptive. The Associational Memory-Appetitive Systems Relations Model of addiction describes how appetitive motives may become excessive, atypically elicited, or misdirected5. There are four main components of this model. First, it is acknowledged that addictions (e.g., alcohol use) have a substantial genetic component (e.g., between 10 and 50% is accounted for by genetics). The model theorizes that one's appetitive needs are impacted by one's genetics. Individuals with a genetic predisposition to substance or behavioral addictions may have a different physiological reaction when engaging in certain behaviors (e.g., involving valence of subjective reward, dissociation of wanting and liking, or involvement of counteradaptation processes). The neurochemistry of an individual can potentially create an inclination toward maladaptive appetitive functioning. DNA epigenetic processes such as cytosine methylation may impact gene expression in the nucleus accumbens (part of an appetitive motivation pathway) subsequent to initial recreational drug intake and possibly involvement in other addictive behaviors. Prolonged periods of stress, particularly at a young age (adverse childhood experiences), may lead to disruption in brain reward cascade functioning. Such disruption, in turn, may increase one's vulnerability to addictive behavioral rewards. Second, the social and physical environmental settings that one traverses will impact what information one learns and how one thinks, and may facilitate which behaviors one may select to perform. Daily life social "pushes" (stresses, social influence) and "pulls" (seductions) provide possible avenues of addiction. For example, encouragement by peers to engage in drug use or marketing the "excitement" of local casinos may push or pull one to explore an addictive substance or behavior. Production and distribution routes of various addictive behaviors will impact what is available to the potential "consumer". Accessibility and awareness of nearby addictive behavior will impact which behaviors one will initiate. Third, one's lifestyle inputs also impact what behaviors may "pop" to mind in daily life. A child who grows up with parents who were engaged in addictive behaviors may be relatively likely to tie appetitive needs fulfillment to an addiction-related lifestyle through vicarious learning3, or else be quite wary to fall victim to such a behavior pattern. In addition, through vicarious experiences, one may learn the vocabulary associated with an addictive behavior (e.g., cannabis "head high" versus a "body high"). That is, one may be socialized and prepared at a young age for entrée into involvement with an addictive behavior later on. When one contemplates trial of an addictive behavior, it should be mentioned that acquisition skills are needed to be able to engage in the behavior with minimal conflict. This includes behavior-specific conversation initiation skills (i.e., knowing how to meet a "supplier" and acquire the addictive behavior; for example, arranging a purchase of cocaine, or time with a sex worker) and a means of exchange (e.g., money or favors for drugs). Involvement in different addictions may vary over the course of human development. For example, persons as young as three years of age may suffer from television addiction. Persons as young as eight years of age may become addicted to caffeine. There are many behaviors that could be experienced as appetitive and become addictive (e.g., tobacco, alcohol, and other drug misuse; binge overeating/food addiction; shopping; electronic media-related; love and sex; workaholism; exercise; and gambling)3. A large minority or a majority of people have tried at least once engaging in various addictive behaviors (e.g., overeating, alcohol use, overspending). More-than-initial trial of an addictive behavior is partly a function of attraction to that behavior. Attraction-related variables include the social image associated with the behavior (e.g., mentioned in the recovery movement, of being "hip, slick and cool"), what one's peers are engaged in (peer social influence), as well neurobiological effects of engaging in the behavior. Fourth, it is through the process of associative learning that appetitive needs come to be subjectively satiated through adaptive or maladaptive behaviors. Associative learning and memory have been considered in several recent models of addictive behaviors. Cues in an environment that otherwise would be considered innocuous can stand out to be emotionally salient when influenced by motivational states6. These cues can range from eating behavior being triggered when seeing fast food sign cues or eating locations, or a drug user becoming excited or agitated when in sight of his/her drug of choice. Some individuals may not, through deliberate cognition, recognize that their decisional processes are being influenced by maladaptive or extreme reward cues. It has been proposed7 that appetitive motivation is controlled through a dual process of deliberate, conscious, executive, regulatory cognition interacting with relatively automatic, implicit processes, in response to addiction-related cues. Over time, in part due to relatively automatic prompting by multiple cues, one may experience excessive thoughts about and desire to perform a behavior. In turn, excessive time may be spent to plan and engage in the behavior, and possibly recover from its effects (e.g., from "hangovers"), and less time may be spent on other activities, despite diminishing appetitive effects1, 8. One is most vulnerable to initial and continued trial of an addictive behavior if the initial consequences are experienced as "filling the gap" in one's sense of well-being (i.e., of being satiated, fulfilled). A widely used saying within the recovery movement is that at first the addiction "does something for the person" and then it "does something to the person". In conclusion, appetitive needs are instinctually embodied in every human being from birth. For at least the past one hundred years, researchers have been exploring the parameters of appetitive needs in human beings9. The interface between one's genetics, social and physical environmental cues, lifestyle situations, development and adaptation (epigenetics and associative learning), and associative memory, may underlie addictive behavior. There is a lot to be learned from an appetitive needs perspective on what is at the root of an addictive process. Appetitive needs which might be explored include those of dominance/leadership, respect, being part of a herd, providing nurturance or being nurtured, and obtaining pleasure3, 5. More research is needed to explore a taxonomy of appetitive needs, and how different appetitive needs act as sources of vulnerability factors and may transform into specific addictive behaviors.