Patterns of use, harm reduction strategies, and their relation to risk behavior and harm in recreational ketamine users.

Background: Recent studies have shown that ketamine use has serious adverse consequences. However, no studies have focused on the strategies that users carry out to protect themselves from such potential harm. Objectives: (i) analyze harm reduction strategies, risk behaviors, and harms in nonmedical/recreational ketamine users; (ii) analyze the association of their harm reduction strategies and risk behaviors with harms they report. Methods: An anonymous cross-sectional web-based survey of 462 persons who had used ketamine in the past year. We designed a questionnaire to collect information on their risk behaviors, harm, and harm reduction strategies. Results: The harms most reported were unexpected confusion (58.2%), memory impairment (57.4%), and abrupt mood/behavior changes (49.6%). The most frequent strategies were spacing out sessions (60.8% always/almost always did this), spacing out doses within a session (54.5%), and limiting the amount and not going over it (41.3%). The use of these three strategies was related to a lower probability of perceiving negative consequences associated with ketamine use, including memory impairment, healthcare assistance, psychological dependence, and risk behaviors related to driving under the influence of ketamine. Conclusions: This study provides empirical evidence on strategies related to the lower probability of harm associated with ketamine use as employed by recreational ketamine users. Our findings suggest that efforts to minimize harm from ketamine use should focus on increasing awareness of potential harms and the use of identified harm reduction strategies.