Hyperventilation syndrome: a chimera?

There is now an impressive body of research to suggest that the concept of a discrete hyperventilation syndrome is no longer tenable. The evidence for this has been carefully gathered and the scientific studies have employed innovative methodological techniques and have introduced a key psychological dimension. Both have led to a greater understanding of the respiratory correlates of anxiety, but in the process have revealed the "hyperventilation syndrome" to be a chimera. Furthermore, there is no evidence to support the view that panic attacks and hyperventilation are synonymous: on the contrary, hyperventilation rarely accompanies panic and, when it does, it is more likely to be a consequence than a cause of the panic. Finally, there is no evidence that "breathing therapy" works by normalizing pCO2; its nonspecific effects on anxiety appear to be mediated in part by slowing respiratory rate. Further research in this field might be more profitably focused on the nature of the association between anxiety disorders and organic lung disease, especially asthma.