PTSD was characterized by attenuated parasympathetic and elevated sympathetic control compared to panic disorder and healthy controls, with group-comparison effect sizes in the order of 1.0.
Cross-Sectional (n=81)
Effect estimate: Effect sizes ~1.0
Objective: Posttraumatic stress disorder (PTSD) and panic disorder (PD) are two anxiety disorders with prominent psychophysiological symptoms. The PTSD criterion of persistent hyperarousal suggests autonomic dysregulation, and the disorder has been associated with elevated heart rate. In contrast, PD has been associated with respiratory abnormalities such as low end-tidal Pco2. An integrated analysis of automatic and respiratory function in a direct comparison of these anxiety disorders is currently lacking. Methods: Electrodermal, cardiovascular, and respiratory psychophysiology was examined in 23 PTSD patients, 26 PD patients, and 32 healthy individuals at baseline and during threat of shock. Results: At baseline, the PTSD patients, in contrast to the other two groups, were characterized by attenuated parasympathetic and elevated sympathetic control, as evidenced by low respiratory sinus arrhythmia (a measure of cardiac vagal control) and high electrodermal activity. They also displayed elevated heart rate and cardiovascular sympathetic activation in comparison with healthy controls. PD patients exhibited lower Pco2 (hypocapnia) and higher cardiovascular sympathetic activation compared with healthy controls. PTSD patients, but not PD patients, sighed more frequently than controls. During the threat of shock phase, the PTSD group demonstrated blunted electrodermal responses. Conclusions: Persistent hyperarousal symptoms in PTSD seem to be due to high sympathetic activity coupled with low parasympathetic cardiac control. Respiratory abnormalities were also present in PTSD. Several psychophysiological measures exhibited group-comparison effect sizes in the order of 1.0, supporting their potential for enhancing differential diagnosis and possibly suggesting utility as endophenotypes in genetic studies of anxiety disorders. CSI = cardiovascular sympathetic index; CVT = cardiac vagal tone; ESI = electrodermal sympathetic index; HR = heart rate; HP = heart period; RSA = respiratory sinus arrhythmia; NS-SCR = number of nonspecific skin conductance fluctuations; HRV = heart rate variability; SCL = skin conductance level; Pco2 = end-tidal partial pressure of expired CO2; PDS = Posttraumatic Diagnostic Scale; PTSD = posttraumatic stress disorder; PD = panic disorder; STAI = State-Trait Anxiety Inventory; BDI = Beck Depression Inventory; SCRamp = amplitude of nonspecific skin conductance responses; ECG = electrocardiogram; lnHF = high-frequency power of HP variability; lnLF = low-frequency power of HP variability; lnVLF = very low-frequency power of HP variability; MANOVA = multivariate analysis of variance; HC = healthy controls.
Blechert et al. (Thu,) conducted a cross-sectional in Posttraumatic stress disorder and panic disorder (n=81). Posttraumatic stress disorder and panic disorder vs. Healthy controls was evaluated on Electrodermal, cardiovascular, and respiratory psychophysiology at baseline and during threat of shock (Effect sizes ~1.0). PTSD was characterized by attenuated parasympathetic and elevated sympathetic control compared to panic disorder and healthy controls, with group-comparison effect sizes in the order of 1.0.