Voluntary breath holding: not a suitable probe of the suffocation alarm in panic disorder.

Voluntary breath-holding duration was investigated in patients with panic disorder, patients with a mood disorder, and normal controls. There were no differences in mean breath-holding durations, but the pattern of scores was different among groups. Furthermore, the scores were influenced by motivational and cognitive factors. It is argued that voluntary breath-holding is not a suitable test to measure carbon dioxide sensitivity or suffocation alarm threshold in panic disorder.