Administration of a single dose of ketamine immediately after the retrieval of alcohol-reward memories disrupts the reconsolidation of these memories and led to reduced drinking levels. The study, which involved 90 participants, is published in Nature Communications.
Reconsolidation is a memory maintenance process, whereby reactivated long-term memories temporarily destabilize in order to incorporate new information. Once destabilized, memories rely on an N-Methyl D-Aspartate Receptor (NMDAR) pathway to reform. It is thought that pharmacological intervention during reconsolidation (using an NMDAR antagonist, such as ketamine) may weaken maladaptive reward memories; for example, those associated with harmful drug-use behaviours.
Ravi Das and colleagues set out to determine if ketamine could weaken memories associated with excessive alcohol-use behaviours and reduce drinking levels. The authors recruited 90 participants with harmful drinking patterns, who did not have a formal diagnosis of alcohol use disorder and were not seeking treatment (55 men and 35 women with an average age of approximately 28 years old). Retrieval of maladaptive reward memories associated with alcohol was induced in the participants by showing them a series of images of beer, after which they received an injection of either ketamine (30) or saline solution (30). Ketamine was also administered to a group of 30 participants without prior memory retrieval. The participants were then asked to report perceived changes in their drinking behaviour (volume, enjoyment and craving) at a number of follow up points. The authors found that treatment with ketamine following memory retrieval led to a reduction in the number of drinking days per week and the volume of alcohol consumed for up to nine months following the intervention in that group. Ketamine in combination with memory retrieval produced a larger magnitude reduction in drinking than administration of ketamine alone.
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