Investigating the effects of caffeine on executive functions using traditional Stroop and a new ecologically-valid virtual reality task, the Jansari assessment of Executive Functions (JEF(©)).

OBJECTIVE: Caffeine has been shown to have effects on certain areas of cognition, but in executive functioning the research is limited and also inconsistent. One reason could be the need for a more sensitive measure to detect the effects of caffeine on executive function. This study used a new non-immersive virtual reality assessment of executive functions known as JEF(©) (the Jansari Assessment of Executive Function) alongside the 'classic' Stroop Colour-Word task to assess the effects of a normal dose of caffeinated coffee on executive function. METHOD: Using a double-blind, counterbalanced within participants procedure 43 participants were administered either a caffeinated or decaffeinated coffee and completed the 'JEF(©)' and Stroop tasks, as well as a subjective mood scale and blood pressure pre- and post condition on two separate occasions a week apart. JEF(©) yields measures for eight separate aspects of executive functions, in addition to a total average score. RESULTS: Findings indicate that performance was significantly improved on the planning, creative thinking, event-, time- and action-based prospective memory, as well as total JEF(©) score following caffeinated coffee relative to the decaffeinated coffee. The caffeinated beverage significantly decreased reaction times on the Stroop task, but there was no effect on Stroop interference. CONCLUSION: The results provide further support for the effects of a caffeinated beverage on cognitive functioning. In particular, it has demonstrated the ability of JEF(©) to detect the effects of caffeine across a number of executive functioning constructs, which weren't shown in the Stroop task, suggesting executive functioning improvements as a result of a 'typical' dose of caffeine may only be detected by the use of more real-world, ecologically valid tasks.

Problematic versus non-problematic ecstasy/MDMA use: the influence of drug usage patterns and pre-existing psychiatric factors.

Recreational ecstasy (3,4-methylenedioxymethamphetamine; MDMA) use has been increasingly associated with a number of psychiatric symptoms and psychological problems. However, previous studies assessing possible psychopathological effects have not identified whether users consider their ecstasy use "problematic" or not. In addition, research has generally failed to address the potential role of premorbid psychiatric status. This study aimed to assess whether premorbid psychiatric history and/or patterns of ecstasy use would be associated with the degree of self-reported problems attributable to ecstasy. Problematic ecstasy users (n = 53) who had reported problems attributable to their ecstasy use were compared with non-problematic ecstasy users (n = 62), polydrug controls (n = 62) and illegal drug-naive controls (n = 111) on a recreational drug use questionnaire; a questionnaire, which ascertained personal and family psychiatric histories, and the Brief Symptom Inventory (BSI). Problematic ecstasy users exhibited significantly higher scores on a number of dimensions of the BSI compared to illegal drug-naive and/or polydrug controls. Problematic ecstasy users also exhibited significantly elevated scores on somatization, depression, anxiety and negative psychobiology compared to non-problematic ecstasy users. BSI scores for the non-problematic ecstasy users did not differ from polydrug or illegal drug-naive controls. Problematic ecstasy users reported significantly higher levels of ecstasy use, including lifetime consumption, average dosage and binge consumption compared to non-problematic ecstasy users. Additionally, a greater number of problematic ecstasy users reported personal and family psychiatric histories compared to controls and non-problematic ecstasy users. This study demonstrates two distinct ecstasy using groups: non-problematic ecstasy users who are not showing signs of psychopathology and problematic ecstasy users who are showing evidence of a range of symptoms. This data therefore partially supports the link between ecstasy dosage and negative psychological sequelae, but highlights the importance of the need to consider ecstasy-related attributions, pre-existing mental health status and vulnerability.

Pattern of cannabis use in ecstasy polydrug users: moderate cannabis use may compensate for self-rated aggression and somatic symptoms.

Cannabis is one of the most common 'co-drugs' for ecstasy users. The aim of the present study was to explore self-reported psychobiological problems in ecstasy polydrug users in relation to their pattern of cannabis use. Two hundred and eighty ecstasy polydrug users were allocated into five cannabis groups according to the frequency of their cannabis use. The control group comprised 121 alcohol-tobacco users. There were no significant group differences with regard to age, diagnosed family psychiatric history and level of self-rated stress experienced during 6 months prior to the study. The present study produced three main findings: (a) Ecstasy users with no concomitant use of cannabis displayed more self-rated aggression and somatic symptoms compared with ecstasy users who were smoking cannabis on a monthly or weekly basis. (b) Ecstasy users who reported heavy cannabis use in the past displayed higher paranoid symptoms compared with ecstasy weekly and daily cannabis users. (c) Former heavy cannabis users were the most likely to complain of a variety of ecstasy related long-term problems. In conclusion, moderate cannabis use may help to ameliorate or mask MDMA-induced aggressivity and somatic symptoms. However, this study confirms that heavy cannabis and ecstasy use is associated with several psychobiological problems, which may emerge after a period of abstinence from both drugs.

Neuropsychological evidence of a relatively selective profile of temporal dysfunction in drug-free MDMA ("ecstasy") polydrug users.

RATIONALE: Experimental evidence has shown that 3,4-methylenedioxymethamphetamine (MDMA, "ecstasy") can act as a serotonergic neurotoxin in laboratory animals. The serotonin system predominantly innervates frontal and limbic regions of the brain and has been associated with consolidatory learning and mnemonic processes in humans. OBJECTIVES: The aim of the present study was to investigate the cognitive neuropsychological profile of drug-free ecstasy users by employing a selection of tasks previously associated with lesion or neurodegenerative damage to the temporal lobe or fronto-striatal regions. METHODS: The study comprised 40 participants: 20 ecstasy polydrug users and 20 polydrug users who had never taken ecstasy. RESULTS: Ecstasy users were significantly impaired on a recognition task for complex visual patterns and spatial working memory, as a function of task difficulty rather than systematic search strategy. They also showed a trend towards impairment on several learning paradigms. Ecstasy users remained relatively unimpaired on most measures associated with prefrontal functioning, with the exception of verbal fluency "letter" generation. CONCLUSIONS: Initial cognitive deficits in ecstasy polydrug users may be more apparent in tasks known to be sensitive to temporal functioning.

Auditory verbal learning in drug-free Ecstasy polydrug users.

Drug-free Ecstasy polydrug users have shown impairment on tasks of verbal working memory and memory span. Current research aims to investigate how these deficits may affect the learning of verbal material by administration of the Auditory Verbal Learning Task (AVLT) (Rey, 1964). The task provides a learning curve by assessing immediate memory span over multiple trials. Learning strategies are further analysed by tendencies to confabulate as well as demonstrate either proactive or retroactive interference elicited by a novel 'distractor' list. Three groups completed the task: two groups of 14 Ecstasy users (short- and long-term) and one group of 14 polydrug controls. Compared with controls both Ecstasy groups recalled significantly fewer words and made more confabulation errors on the initial three recall trials as well as a delayed recall trial. Long-term users demonstrated increased confabulation on the initial trials and the novel 'distractor7' trial, compared with short-term users. Only following repeated presentations were both short- and long-term users shown to perform at control levels. As such, deficits in verbal learning may be more related to storage and/or retrieval problems than problems associated with capacity per se. No interference errors were demonstrated by either of the Ecstasy groups. However, a high level of intrusion errors may indicate selective working memory problems associated with longer-term use of the drug. Copyright 2001 John Wiley & Sons, Ltd.

Psychiatric disorders in Ecstasy (MDMA) users: a literature review focusing on personal predisposition and drug history.

3,4-methylenedioxymethamphetamine (MDMA or Ecstasy) has been implicated in the onset of a number of psychological disorders and associated with a number of psychiatric symptoms that have persisted after cessation of the drug. This paper is a review of the published psychiatric case studies from the last 10 years involving MDMA. Only 24% of patients had a previous psychiatric history and 34% had a psychiatric illness amongst first degree relatives. The percentage of patients not having had a personal or family history of psychiatric illness and the temporal relationship between MDMA ingestion and the experience of recurring symptoms strongly suggest a causal relationship between the drug and neuropsychiatric manifestations. Further supporting evidence comes from several studies using non-clinical samples. Ecstasy users that don't present themselves in healthcare settings as having clinical symptoms have significantly higher scores on certain subscales of the SCL-90 compared with Ecstasy-naive controls, with higher pathology scores in heavier Ecstasy users. The full-blown psychiatric cases may represent the broad end of this problematic spectrum. Copyright 2001 John Wiley & Sons, Ltd.