Cognitive task performance was assessed in three groups of young people: 10 regular users of 3,4-methylenedioxymethamphetamine (MDMA) who had taken 'ecstasy' 10 times or more; 10 novice MDMA users who had taken 'ecstasy' one to nine times; and 10 control subjects who had never taken MDMA. A computerized battery of cognitive tasks (Cognitive Drug Research system) was undertaken on a day when subjects were drug free. Performance on the response speed and vigilance measures (simple reaction time, choice reaction time, number vigilance), was similar across the three subgroups. However on immediate word recall and delayed word recall, both groups of MDMA users recalled significantly less words than controls. Animal research has shown that MDMA can lead to serotonergic neurodegeneration, particularly in the hippocampus and frontal cortex. Although the design of this study was far from ideal, these data are consistent with other findings of memory decrements in recreational MDMA users, possibly caused by serotonergic neurotoxicity.

Regular cigarette smokers (n 15), overnight deprived smokers (n 15) and nonsmokers (n 20), were assessed on a battery of mood questionnaires and cognitive performance tasks, before and after a cigarette/rest period. At the initial session, deprived smokers reported signi®cantly greater feelings of stress, irritability, depression, poor concentration and low pleasure, than both nondeprived smokers and nonsmokers (all comparisons, p 5 0 . 01). After the rest/cigarette break, the mood states of all three groups became generally similar, although the previously deprived smokers still reported elevated depression. These ®ndings suggest that mood gains after smoking re¯ect the simple reversal of abstinence eects. On the cognitive tasks, there were no signi®cant dierences in letter cancellation performance between subgroups, either before or after smoking. With mental arithmetic, abstinent and nonabstinent smokers attempted more problems than nonsmokers, both before and after the rest/cigarette break. This is suggestive of faster cognitive processing in smokers, irrespective of their nicotine status. However, the cognitive performance data were untypical in various ways and need replication. #

Twenty regular smokers were assessed over 24-h of normal cigarette smoking, and an equivalent period of abstinence. In both conditions, a non-deprived baseline was followed by performance tests 2, 6 and 24 h later, while subjective feelings were assessed every 2 h. Compared to normal smoking, abstinence led to reduced heart rate, worse task performance, feelings of depression, stress, irritability, restlessness, poor concentration, and urges to smoke. Letter cancellation and number vigilance task performance were significantly poorer after 2 and 6 h of abstinence. Subjective feeling states were significantly worse after 4 h of abstinence, and became increasingly impaired over the rest of the day. However many abstinence symptoms (except heart rate), were reduced in severity at the 24-h session, held on the morning of the following day. This suggests that many of the psychological effects of smoking abstinence, may build-up afresh each day.

No abstract