Harms associated with psychoactive substances: findings of the UK National Drug Survey.

Nutt and colleagues' 'rational' scale to assess the harms of commonly used drugs was based on ratings by a panel of experts. This survey aimed to assess drug users' views of the harms of drugs using the same scale. As users' drug choices are not solely based on harms, we additionally assessed perceived benefits.

Consequences of chronic ketamine self-administration upon neurocognitive function and psychological wellbeing: a 1-year longitudinal study.

Background: 'Recreational' use of ketamine is spreading rapidly among young people. In healthy individuals an acute dose of the N-methyl D-aspartate (NMDA) receptor antagonist ketamine induces marked psychosis-like effects and cognitive impairments, but little is known about the long-term effects of the drug.

Aims: To evaluate the long-term neuropsychiatric or cognitive consequences.

Ketamine use, cognition and psychological wellbeing: a comparison of frequent, infrequent and ex-users with polydrug and non-using controls.

Introduction: Preliminary research has indicated that recreational ketamine use may be associated with marked cognitive impairments and elevated psychopathological symptoms, although no study to date has determined how these are affected by differing frequencies of use or whether they are reversible on cessation of use. In this study we aimed to determine how variations in ketamine use and abstention from prior use affect neurocognitive function and psychological wellbeing.

Method: We assessed a total of 150 individuals: 30 frequent ketamine users, 30 infrequent ketamine users, 30 ex-ketamine users, 30 polydrug users and 30 controls who did not use illicit drugs.

Perceptual organization in ketamine users: preliminary evidence of deficits on night of drug use but not 3 days later.

N-methyl-D-aspartate (NMDA)-receptor antagonists such as ketamine can induce transient schizophrenia-like symptoms and cognitive dysfunctions in healthy volunteers similar to those observed in patients with schizophrenia. Perceptual organization deficits have been documented in schizophrenia and are thought to be related to some symptoms associated with the illness. The current study was designed to determine whether people who repeatedly self-administer ketamine would also show deficits in perceptual organization.