35% CO2 sensitivity in social anxiety disorder

The 35% carbon dioxide (CO2) challenge is a well-established model of panic. This study aimed to investigate 35% CO2 sensitivity in patients with social anxiety disorder (SAD) compared with patients with panic disorder (PD) and normal controls. First, a 35% CO2 challenge was conducted including 16 patients with generalized SAD, 16 with PD and 16 normal subjects. Outcome was assessed by a Visual Analogue Scale for Fear (VAS-F) and the Panic Symptom List (PSL). Second, meta-analyses of fear and panic scores were performed, including data from the present experiment and from previous 35% CO2 challenge studies in patients with SAD. The present 35% CO2 challenge found equal increases in VAS-F and PSL in patients with SAD compared with normal controls, whereas the CO2 response in patients with PD was significantly stronger than in controls. The meta-analyses confirmed the experimental data from this study, and in addition showed an intermediate panic rate in SAD patients, in between that of normal controls and ...