Panic disorder (PD) pathophysiology is very heterogeneous, and the discrimination of distinct subtypes could be very useful. A subtype based on respiratory symptoms is known to constitute a specific subgroup. However, evidence to support the respiratory subtype (RS) as a distinct subgroup of PD with a well-defined phenotype remains controversial. Studies have focused on characterization of the RS based on symptoms and response to CO2. In this line, we described clinical and biological aspects focused on symptomatology and CO2 challenge tests in PD RS. The main symptoms that characterize RS are dyspnea (shortness of breath) and a choking sensation. Moreover, patients with the RS tended to be more responsive to CO2 challenge tests, which triggered more panic attacks in this subgroup. Future studies should focus on discriminating respiratory-related clusters and exploring psychophysiological and neuroimaging outcomes in order to provide robust evidence to confirm RS as a distinct subtype of PD.

中文翻译：

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恐慌症呼吸亚型：精神病理学和挑战测试——更新

恐慌症 (PD) 的病理生理学是非常异质的，区分不同的亚型可能非常有用。已知基于呼吸道症状的亚型构成特定的亚组。然而，支持呼吸亚型 (RS) 作为具有明确表型的不同 PD 亚组的证据仍然存在争议。研究的重点是根据症状和对 CO2 的反应来表征 RS。在这方面，我们描述了临床和生物学方面，重点是 PD RS 中的症状学和 CO2 挑战测试。RS 的主要特征是呼吸困难（气短）和窒息感。此外，RS 患者往往对 CO2 挑战测试更敏感，这在该亚组中引发了更多的惊恐发作。