As is now more widely recognized, Panic Disorder often results in considerable emotional suffering and a reduction in quality of life. Although progress has been made in identifying its biological substrates, much about its pathophysiology and etiology remains obscure. Latest research findings in our laboratory and laboratories of other research groups point towards a central role for respiratory mechanisms. Experiments are proposed to investigate markers and mechanisms of Panic Disorder in and outside the laboratory. Respiratory, sympathetic, and parasympathetic measures in Panic Disorder patients of two types, those with and without prominent respiratory symptoms, will be examined and compared to measures in two groups without panic attacks, Generalized Anxiety Disorder patients and controls. In the laboratory the relative importance of several possible respiratory mechanisms will be determined by examining probe-specific and group-specific effects of several kinds of probes: increased inspired CO2, increased inspiratory resistance load, and decreased inspired O2. Each is known to produce feelings of suffocation at moderate intensities, and sometimes panic in Panic Disorder patients at high intensities. Respiratory responses to a noise stressor not directly linked to suffocation fears will serve as a comparison. To resolve contradictions in the literature about slower recovery from voluntary hyperventilation in Panic Disorder, which was a specific marker for Panic Disorder in one of our recent experiments, the effects of different durations of hyperventilation will be examined. In another experiment, central and peripheral chemoreceptor thresholds and sensitivities will be distinguished in Panic Disorder for the first time. Outside the laboratory two ways of recording pCO2 (transcutaneous vs. nasal prongs) will be compared methodologically, and it will be determined whether valid indices of respiratory sinus arrhythmia that take into account variations in breathing will distinguish patients with panic attack-related driving phobia from controls. The significance of this proposal lies in the possibility of its establishing specific and sensitive physiological markers of Panic Disorder, which could lead to better diagnosis and more appropriate treatment, facilitate research in the molecular genetics of Panic Disorder, and lead to a better understanding of dysfunctional biological control mechanisms.

Agency
National Institute of Health (NIH)
Institute
National Institute of Mental Health (NIMH)
Type
Research Project (R01)
Project #
5R01MH056094-06
Application #
6538765
Study Section
Special Emphasis Panel (ZRG1-BBBP-2 (01))
Program Officer
Dolan-Sewell, Regina
Project Start
1997-05-15
Project End
2004-04-30
Budget Start
2002-05-01
Budget End
2004-04-30
Support Year
6
Fiscal Year
2002
Total Cost
$292,500
Indirect Cost
Name
Stanford University
Department
Psychiatry
Type
Schools of Medicine
DUNS #
800771545
City
Stanford
State
CA
Country
United States
Zip Code
94305
Blechert, Jens; Wilhelm, Frank H; Meuret, Alicia E et al. (2013) Experiential, autonomic, and respiratory correlates of CO2 reactivity in individuals with high and low anxiety sensitivity. Psychiatry Res 209:566-73
Ritz, Thomas; Rosenfield, David; Wilhelm, Frank H et al. (2012) Airway constriction in asthma during sustained emotional stimulation with films. Biol Psychol 91:8-16
Meuret, Alicia E; Rosenfield, David; Wilhelm, Frank H et al. (2011) Do unexpected panic attacks occur spontaneously? Biol Psychiatry 70:985-91
Blechert, Jens; Wilhelm, Frank H; Meuret, Alicia E et al. (2010) Respiratory, autonomic, and experiential responses to repeated inhalations of 20% CO? enriched air in panic disorder, social phobia, and healthy controls. Biol Psychol 84:104-11
Burkhardt, Susan C A; Wilhelm, Frank H; Meuret, Alicia E et al. (2010) Temporal stability and coherence of anxiety, dyspnea, and physiological variables in panic disorder. Biol Psychol 85:226-32
Ritz, Thomas; Wilhelm, Frank H; Meuret, Alicia E et al. (2009) Do blood phobia patients hyperventilate during exposure by breathing faster, deeper, or both? Depress Anxiety 26:E60-7
Meuret, Alicia E; Wilhelm, Frank H; Ritz, Thomas et al. (2008) Feedback of end-tidal pCO2 as a therapeutic approach for panic disorder. J Psychiatr Res 42:560-8
Wilhelm, Frank H; Pfaltz, Monique C; Grossman, Paul et al. (2006) Distinguishing emotional from physical activation in ambulatory psychophysiological monitoring. Biomed Sci Instrum 42:458-63
Alpers, Georg W; Wilhelm, Frank H; Roth, Walton T (2005) Psychophysiological assessment during exposure in driving phobic patients. J Abnorm Psychol 114:126-39
Roth, Walton T; Wilhelm, Frank H; Pettit, Dean (2005) Are current theories of panic falsifiable? Psychol Bull 131:171-92

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