Platelet serotonin binding and plasma cortisol in panic disorder before and after alprazolam plus behavioral guidance treatment

In 32 patients with panic disorder with or without agoraphobia B(max) measures of 5-HT binding in platelets did not differ from normal controls at baseline. Plasmatic cortisol levels were significantly higher than controls in the morning and in the evening measures as well as in post-dexamethasone assays. Following an 8-week treatment period with alprazolam plus behavioral guidance encouraging exposure, B(max) values did not alter but cortisol measures diminished significantly. Measures of phobic avoidance were negatively correlated with 5-HT B(max) values. Plasmatic cortisol correlated positively with the number of situational panic attacks in the month before treatment. There were no correlations between cortisol and 5-HT B(max) measures. A possible link between serotonin function and phobic avoidance is discussed. Cortisol changes were interpreted as being related to the global severity of the anxious state.