Drug-Induced Glucocorticoids and Memory for Substance Use

Abstract

The biological stress response of the body forms one of the foundations of adaptive behavior, including promoting (and impairing) different forms of memory. This response transcends stressful experiences and underlies reactions to challenges and even reinforcers such as addictive substances. Nevertheless, drug-induced stress responses are rarely incorporated into models of addiction. We propose here that drug-induced stress responses (particularly glucocorticoids) play a crucial role in addictive behavior by modulating the formation of memories for substance-use experiences. We review the contributions of amygdala-, striatum-, and hippocampus-based memory systems to addiction, and reveal common effects of addictive drugs and acute stress on these different memories. We suggest that the contributions of drug-induced stress responses to memory may provide insights into the mechanisms driving addictive behavior.

Keywords: addiction; amygdala; hippocampus; memory; stress; striatum.

Figure I

(for Box 1). Illustration of multiple memory systems in a drug-use episode. Top, an episode of substance use. Bottom, illustration of the different memories (associated with different memory systems) that can be formed during such an episode. Blue: dorsolateral striatum-dependent cue-response association; green: amygdala-dependent cue-affect association; red: hippocampus-dependent cue-cue (context) association. Note that other brain regions are also involved in the encoding and retrieval of these associations; here we focus on the critical “hubs” in these memory systems.