Psychoimmunoendocrine aspects of panic disorder

Stress-responsive neurohormonal systems are involved in major depression (MD) and panic disorder (PD). The immune system, which is closely connected with neuronal and hormonal systems, has been studied in MD: a systemic immune activation has been recently reported. To determine whether similar changes in the immune function are present also in PD, we studied leukocyte enumeration by flow cytometry in conjunction with monoclonal antibody staining, in 18 PD, 23 MD in drug-free conditions and 20 controls. We found a significantly higher percentage of HLADR+(p<0.001) and of CD19 cells (p<0.01) in PD and MD and a lower percentage of CD3 (p<0.05) in PD. Urinary free cortisol levels were higher in MD compared to PD. A pattern of lymphocyte subpopulation distribution compatible with an activation of the immune system was found in MD and PD. This activation was present also with high glucocorticoid levels, suggesting a possible defect of glucocorticoid receptors.