James Jack E, Keane Michael A
Department of Psychology, National University of Ireland, Galway, Ireland.
Hum Psychopharmacol. 2007 Dec;22(8):549-58. doi: 10.1002/hup.881.
The broad aim of this review is to critically examine the implications of new understanding concerning caffeine withdrawal and withdrawal reversal in the context of research concerned with the effects of caffeine on sleep and wakefulness. A comprehensive search was conducted for relevant experimental studies in the PubMED and PsycINFO databases. Studies were assessed with particular reference to methodological adequacy for controlling against confounding due to caffeine withdrawal and withdrawal reversal. This assessment was used to clarify evidence of effects, highlight areas of ambiguity and derive recommendations for future research. It was found that researchers have generally failed to take account of the fact that habitual use of caffeine, even at moderate levels, leads to physical dependence evidenced by physiological, behavioural and subjective withdrawal effects during periods of abstinence. Consequently, there has been near-complete absence of adequate methodological controls against confounding due to reversal of withdrawal effects when caffeine is experimentally administered. The findings of what has been a substantial research effort to elucidate the effects of caffeine on sleep and wakefulness, undertaken over a period spanning decades, are ambiguous. Current shortcomings can be redressed by incorporating suitable controls in new experimental designs.
本综述的主要目的是，在有关咖啡因对睡眠和觉醒影响的研究背景下，批判性地审视关于咖啡因戒断及戒断逆转的新认识所带来的影响。我们在PubMed和PsycINFO数据库中对相关实验研究进行了全面检索。评估研究时特别参考了控制咖啡因戒断和戒断逆转所导致的混杂因素的方法学充分性。该评估用于阐明效应证据、突出模糊领域并为未来研究提出建议。结果发现，研究人员普遍未能考虑到以下事实：即使是适度使用咖啡因，长期使用也会导致身体依赖，在戒断期间会出现生理、行为和主观的戒断效应。因此，在通过实验给予咖啡因时，几乎完全缺乏针对戒断效应逆转所导致的混杂因素的充分方法学控制。在数十年时间里为阐明咖啡因对睡眠和觉醒的影响而进行的大量研究努力，其结果并不明确。通过在新的实验设计中纳入适当的对照，可以弥补当前的不足。
