A review of psychological factors/processes affecting anxious responding during voluntary hyperventilation and inhalations of carbon dioxide-enrichedair

Despite advances in our understanding of the nature of anxiety-related resp onding during periods of elevated bodily arousal, it is not necessarily evi dent by what psychological mechanisms anxiety is produced and maintained. T o address this issue, researchers have increasingly employed biological cha llenge procedures to examine how psychological factors affect anxious respo nding during elevated bodily arousal. Of the challenging procedures, hyperv entilation and inhalations of carbon dioxide-enriched air have been among t he most frequently employed, and a relatively large body of literature usin g these procedures has now accumulated. Unfortunately, existing reviews do not comprehensively examine findings from hyperventilation and inhalations of carbon dioxide studies, and only rarely the methodological issues specif ic to these studies. To address these issues, we review the voluntary hyper ventilation and carbon dioxide-enriched air literature in order to identify the primary methodological issues/limitations of this research and address the extent to which psychological variables influence anxious responding t o such challenges. Overall we conclude challenge research is a promising pa radigm to examine the influence of psychological variables in anxious respo nding, and that such work will likely be enhanced with greater attention to psychological process issues. (C) 2001 Elsevier Science Ltd.