MDMA, cannabis, and cocaine produce acute dissociative symptoms

Introduction

Dissociative symptoms encompass a heterogeneous set of experiences ranging from absent-mindedness and excessive daydreaming to severe states such as dissociative amnesia and depersonalization/derealization disorder. These symptoms occur across a range of psychiatric diagnoses and can also appear acutely during intoxication with various drugs. Previous experimental work has shown that subanaesthetic ketamine produces depersonalization and derealization in healthy volunteers, and observational studies have linked regular MDMA and cannabis use with mild depersonalization/derealization experiences, but the dissociative potential of commonly used recreational drugs has been understudied and remains incompletely characterised. Van Heugten-Van Der Kloet and colleagues set out to explore the acute dissociative effects of three recreational drugs—MDMA, cannabis and cocaine—using placebo-controlled experimental designs. The investigators aimed to test whether these substances increase state dissociation during intoxication, whether effects are dose-dependent (for MDMA), and how drug-induced dissociation compares with dissociation reported in clinical and extreme-stress samples (schizophrenia patients, Special Forces soldiers during survival training) and with ketamine intoxication. The study therefore combined experimental drug challenges with comparisons to previously published CADSS (Clinician-Administered Dissociative States Scale) data from other samples to gauge clinical relevance.