The Acute Effects of Psychoactive Drugs on Emotional Episodic Memory Encoding, Consolidation, and Retrieval

Introduction

The authors situate their review within growing interest in how psychoactive drugs affect human episodic memory, arguing that episodic memory—conscious recollection of discrete events—may be especially relevant to understanding both recreational drug use and therapeutic effects. Earlier work has mainly examined procedural or conditioning forms of learning, but episodic memory captures idiosyncratic, emotionally charged experiences that can shape later behaviour (for example, promoting “chasing the first high” or influencing affective disorder symptoms). Affective disorders often involve altered emotional episodic memory (e.g. enhanced memory for negative events), and several psychoactive compounds under investigation for therapeutic use (cannabis, ketamine, MDMA, psilocybin, scopolamine) may also alter memory processes; thus understanding drug effects on emotional episodic memory is important for both harm and benefit considerations. This review sets out to summarise human experimental work on the acute effects of psychoactive drugs on three phases of episodic memory—encoding (formation), consolidation (stabilisation), and retrieval (access)—with an emphasis on objective memory tests that included neutral and emotionally valenced (negative and/or positive) stimuli. The authors consider a range of drug classes (GABAA sedatives including alcohol and benzodiazepines, THC, stimulants, MDMA, ketamine, scopolamine, nicotine, and GHB), discuss how timing of administration is used to target memory phases, review behavioural and some neuroimaging findings, and propose neural mechanisms and clinical implications. The focus is on acute pharmacological manipulations in humans; the authors note that, in the extracted text, no studies testing opioids or classic psychedelics on objective emotional episodic memory tasks were identified.