Psychological effects of ketamine: a research note

Abstract

PurposeKetamine intoxication has been mooted as a model of some of the signs and symptoms of psychosis. However, little research has focused on the self‐report experience of ketamine users. The purpose of the current study is to quantify (the frequency of occurrence of) ketamine induced phenomenology in recreational users. The paper also seeks to meaningfully group these experiences into facets and their principal components.Design/methodology/approachRespondents completed a checklist of experiences, the Ketamine Experiences Questionnaire (KEQ). Two samples were recruited via opportunity and snowball sampling one in 2009 (n=52) and one in 2010/11 (n=35).FindingsThe “Q‐sort” and principal component analysis (PCA) indicate that there are two factors, factor one representing aversive ketamine experiences (accounting for 48.2 per cent of the variance) and factor two representing appetitive ketamine experiences (accounting for 20.1 per cent of the variance). Ketamine induces a raft of appetitive, aversive and transcendental experiences many of which are illustrated. The data suggest that a decision about whether to continue using ketamine (and if so, how often) depends in part on an intuitive cost‐benefit analysis of the phenomenology that it induces.Research limitations/implicationsThere are some notable limitations to the current study; the small sample size to variable ratio necessitated a “Q‐sort” before PCA; the sampling procedure prohibited the generation of a representative sample; and there were no means of independently verifying ketamine use.Originality/valueThis study represents a novel exploration into ketamine phenomenology and the principal components of these experiences.