Memory Systems and the Addicted Brain

Abstract

The view that anatomically distinct memory systems differentially contribute to the development of drug addiction and relapse has received extensive support. The present brief review revisits this hypothesis as it was originally proposed 20 years ago (1) and highlights several recent developments. Extensive research employing a variety of animal learning paradigms indicates that dissociable neural systems mediate distinct types of learning and memory. Each memory system potentially contributes unique components to the learned behavior supporting drug addiction and relapse. In particular, the shift from recreational drug use to compulsive drug abuse may reflect a neuroanatomical shift from cognitive control of behavior mediated by the hippocampus/dorsomedial striatum toward habitual control of behavior mediated by the dorsolateral striatum (DLS). In addition, stress/anxiety may constitute a cofactor that facilitates DLS-dependent memory, and this may serve as a neurobehavioral mechanism underlying the increased drug use and relapse in humans following stressful life events. Evidence supporting the multiple systems view of drug addiction comes predominantly from studies of learning and memory that have employed as reinforcers addictive substances often considered within the context of drug addiction research, including cocaine, alcohol, and amphetamines. In addition, recent evidence suggests that the memory systems approach may also be helpful for understanding topical sources of addiction that reflect emerging health concerns, including marijuana use, high-fat diet, and video game playing.

Enhancement of striatum-dependent memory by conditioned fear is mediated by beta-adrenergic receptors in the basolateral amygdala

“…Finally, numerous investigators have suggested that enhancement of the dorsal striatum-dependent memory system might in part underlie the development of some neuropsychiatric disorders, in particular disorders with prominent habit-like behavioral features (White, 1996, Everitt and Robbins, 2005, Schwabe et al., 2011a, Berner and Marsh, 2014, Gillan and Robbins, 2014, Goodman et al., 2014, Goodman and Packard, 2016a, Goodman and Packard, 2016b). For instance, post-traumatic stress disorder (PTSD) is partly characterized by intractable avoidance behaviors that occur in response to trauma-related cues, and some investigators suggest that such avoidance symptoms may be a manifestation of enhanced DLS-dependent habit memory following very high levels of emotional arousal (i.e., trauma; Packard, 2009, Schwabe et al., 2010c, Goodman et al., 2012).…”

The neurobiology of the emotional adolescent: From the inside out

“…An increased desire to try new things, a need to ramp up one’s emotional state, and/or heightened worry over fitting in socially may tip adolescents into long-term maladaptive patterns. As an example, substance experimentation for some adolescents may alter neural circuitry underlying affective and cognitive processing and create reinforcing habits over time that lead to long term substance use disorders (Goodman and Packard, 2016). These mechanisms may be further enhanced by stressful experiences that are commonly encountered in adolescence (Goodman and Packard, 2016; Romeo, 2010; Spear, 2009).…”

Effects of drugs of abuse on hippocampal plasticity and hippocampus-dependent learning and memory: contributions to development and maintenance of addiction

“…This behavioral plasticity, often times maladaptive, must be associated changes in neural plasticity. In fact, it has been noted multiple times that there is a high degree of overlap between the neurobiology of learning and memory and the neurobiology of addiction (e.g., White 1996;Kelley 2004;Hyman et al 2006;Volkow et al 2014;Goodman and Packard 2016). Drugs of abuse are often linked to disrupted learning, but the relationship between drugs of abuse and learning is more complex as drug use and abuse is also associated with the development of strong but maladaptive memories that contribute to drug-seeking behavior and addiction.…”