Ecstasy-related deficits in the updating component of executive processes

Aims Research shows that users of ecstasy (MDMA) exhibit deficits in executive processes. The updating component appears to be particularly susceptible. Less is known about the precise nature of such deficits. The present study sought to determine if ecstasy-related deficits in memory updating are related to serial position of items presented, or length of the list of items. Method Seventy-three ecstasy/polydrug users and seventy-three non-ecstasy users completed tasks of verbal and spatial memory running memory, recalling the most recent items, in lists of varying and unknown length. Participants were categorised according to letter and spatial span (four, five or six), producing six sub-samples for analysis. Results Ecstasy-polydrug users were impaired in four out of the six sub-sample analyses. Three of these were due to impaired recall of earlier serial positions. Conclusions The results of the present study provide further support for updating deficits in ecstasy-polydrug users. The results are suggestive of a breakdown in the maintenance of information in working memory in terms of chunking; it appears that ecstasy/polydrug users are as able as non-ecstasy users to form memory 'chunks' from the items, but that such chunks are not retained as effectively. Copyright (C) 2008 John Wiley & Sons, Ltd.