EFFECT OF DEPRESSIVE EMOTIONS ON AIRWAYS IN ASTHMA

描述（改编自申请人摘要）：本研究的目的

DESCRIPTION (Adapted from the Applicant's Abstract): The objective of the proposed project is to apply a unique conceptual model and laboratory, method, developed by the P.I., to investigate conditions under which, and mechanisms by which, depressive emotional states affect autonomic processes associated with airways function in asthma. This objective will be accomplished by further testing and elaborating the Autonomic (ANS) Dysregulation Model of Emotional Influence on Asthma (Miller 1987, Miller & Wood, 1997) which proposes that depressed, despairing or hopeless emotional states are associated with ANS dysregulation such that a cholinergic (PNS) bias potentiates cholinergically (PNS) mediated airways constriction! giving rise to a psychophysiologically vulnerable asthmatic state. The movie "E.T., the Extra-Terrestrial" will be used to provide emotion-specific challenges to 138 male and 138 female adolescents, ages 11-16 (Tanner stages 2-5), with asthma, while continuously measuring autonomic nervous system (ANS) modulation of the cardio-respiratory system and airway function. Scenes evoking fear, sadness/hopelessness, happiness/excitement and mixed sadness/happiness will be compared to each other and to a neutral scene and baseline. Salivary cortisol and airway function (FEV1) measures will be taken pre and post movie and after each scene. Oxygen saturation will be measured throughout the movie. Subjects' asthma and emotional state will be profiled before the movie. Airway reactivity will be measured by methacholine challenge test (PC20). Hopeless/depressed states will be assessed by the Hopelessness Scale for Children and the Child Depression Inventory, adjusted for anxiety. Autonomic (SNS and PNS) reactivity is reflected by heart rate responses to experimentally induced emotional challenge, i. e., the "movie". Two convergent methods Will he used differentiate sympathetic (SNS) from parasympathetic (PNS) modulation of the cardio-respiratory system: 1) impedance cardiography (PEP) for SNS, respiratory sin us arrhythmia (RSA) for PNS; 2) and Power Spectral Analysis (PSA) of heart rate variability (HRV), which yields indices of SNS and PNS. Hypothesized relationships between PC20, hopeless/depressed states, PNS and SNS activation, cortisol and airways function will be tested. Multiple regression and repeated measures analysis of variance methods will be used to analyze the data. Medication effects will be assessed and analyses covaried if necessary.