OVERREACTIVITY OF THE PSYCHE OR THE SOMA - INTERINDIVIDUAL ASSOCIATIONS BETWEEN PSYCHOSOMATIC SYMPTOMS, ANXIETY, HEART-RATE, AND END-TIDAL PARTIAL CARBON-DIOXIDE PRESSURE

Current research has all but refuted previous suggestions about the ro le of hyperventilation as a proximal, common cause of psychosomatic sy mptoms. As an alternative, it has been proposed that the experience of psychosomatic symptoms is primarily associated with psychological mec hanisms, i.e., with enhanced tendencies of distressed individuals to f ocus their attention on bodily sensations and to evaluate these in a c atastrophic manner. Although this hypothesis has received considerable empirical support, physiological influences on symptom reporting have not, as yet, been fully explored, In this study, contributions of psy chological and physiological factors were studied among a group of 83 normal healthy male subjects by an assessment of the interindividual r elationships between symptom experience in daily life, situational and dispositional anxiety, baseline end-tidal partial carbon dioxide pres sure (PCO2), and heart rate. Trait anxiety and end-tidal PCO2 each con tributed separately to the prediction of the psychosomatic symptom sco re. Trait anxiety explained nearly one third of the symptom variance, and an additional 4% was explained by PCO2. Psychological symptoms wer e more strongly associated with anxiety and somatic symptoms, more str ongly with PCO2. Heart rate only tended to be correlated with symptom reporting. Analysis of covariance among subgroups of extreme-symptom r eporters supported the correlational findings by demonstrating that th e association between hyperventilation and symptom reporting remained intact when psychological influences were factored out. The findings s uggest that reports of psychosomatic symptoms represent two distinct c omponents: one that is primarily psychological (and is unrelated to ph ysiological factors) and a second that reflects objective variance in physiological functioning. The influence of the first component is pro bably greater than that of the second.