The effect of stress on salivary cortisol in panic disorder patients

Background. Various findings suggest the possibility of an abnormal cortiso l response to CRH in panic disorder patients, which raises the question of whether such patients might also produce an abnormal cortisol response to s tress. The purpose of the present study was to use salivary cortisol measur ement in assessing differences in response to novelty/mild stress situation s between panic disorder subjects and controls. Methods. Subjects were recr uited by means of posters and subsequently screened for suitability as cont rols or panic subjects. Twenty-four panic disorder (PD) sufferers and 15 pa nic-free control subjects were tested on a range of psychometric and physio logical measures, at both the start and the end of the experiment. Subjects were tested at the beginning for state anxiety, salivary cortisol, heart r ate, and blood pressure, and these tests were repeated at the end of the se ssion (which had been designed to promote reassurance). Results. The state anxiety scores (STAI) showed a reduction in anxiety level over the test per iod, and there was a corresponding fall in both blood pressure and heart ra te for both groups. Cortisol levels also fell over the course of the interv iew in the control group, but in the PD group cortisol levels showed no suc h reduction. In addition, there was a significant difference in the levels of cortisol at the start of the session between the two groups (PD group lo wer). Conclusions. These data indicate a possible alteration in cortisol re sponsiveness to stress/novelty situations in PD subjects. This was consider ed to be consistent with previous suggestions of HPA axis dysregulation in PD patients, although our research indicates unresponsiveness rather than r esponsiveness to be a factor to be considered for future investigation. Cli nical Implications. Our results suggest that not all subjects suffering PD may benefit from stress reduction therapies as a first choice of treatment for their panic attacks. The existence of nocturnal panic attacks (consider ing sleep as a combination of mental and physical relaxation), in the absen ce of nightmares, as well as the induction of panic attacks during relaxati on support this view. Limitations of the Study. Apart from the difficulty i n accessing sufficient symptomatic subjects, the induction of higher levels of stress could be useful for confirmation of these results. However, this requires specialist support in case of subjects developing panic attacks d uring the experiments, which was not available during the present study. Su mmary. Twenty-four panic disorder (PD) sufferers and 15 panic-free control subjects were tested on a range of psychometric and physiological measures, at both the start and the end of an experimental session. Subjects were te sted at the beginning for state anxiety, salivary cortisol, heart rate, and blood pressure, and these tests were repeated at the end of the session. T he state anxiety scores (STAI) showed a reduction in anxiety level over the test period for both groups, and there was a corresponding fall in both bl ood pressure and heart rate. Cortisol levels also fell over the course of t he session in the control group, but in the PD group cortisol levels showed no such reduction. In addition, there was a significant difference in the levels of cortisol at the start of the session between the two groups (PD g roup lower). These data indicate a possible alteration in cortisol responsi veness to stress/novelty situations in PD subjects. This was considered to be consistent with previous suggestions of HPA axis dysregulation in PD pat ients, although our research indicates unresponsiveness rather than respons iveness to be a factor to be considered for future investigation. (C) 1999 Elsevier Science B.V. All rights reserved.