RESUMEN
Although recreational use of the dissociative anaesthetic drug ketamine is currently increasing, little is known about the phenomenological aspects of its use. We therefore designed a structured interview to examine initiation experiences, positive and negative effects of ketamine use, and concerns about the drug and its long-term effects. Ninety participants (30 frequent users, 30 infrequent 'recreational' users and 30 ex-users who had abstained from use for at least 3 months) were interviewed and reported drug use was verified by hair sample analysis. The most appealing aspects of ketamine for two-thirds of users were "melting into the surrounding", "visual hallucinations", "out-of-body experiences" and "giggliness". Unappealing effects for half of users were "memory loss" and "decreased sociability". Frequent ketamine users expressed more concerns than other groups about long-term effects on physical health problems, especially K-cramps and cystitis, whereas ex-users were more concerned about mental health problems. Addictive/dependent patterns of behaviour were also a concern: the majority of frequent users reported using the drug without stopping until supplies ran out and the mean increase in dosage in this group was six-fold from initiation to current use. We have identified specific health issues which seem uniquely related to ketamine use. Additionally, the dependence on ketamine frequently reported by users may be a cause for concern as its popularity grows and substance misuse services should be made aware of this when clients present in the future.