PAROXETINE BINDING IN THE BLOOD-PLATELETS OF POSTTRAUMATIC-STRESS-DISORDER PATIENTS

Platelet serotonin (5-HT) uptake, as determined by H-3-paroxetine (PA) binding, was studied in 20 Post-traumatic Stress Disorder (PTSD) patients and 20 normal controls. K(d) (an inverse measure of affinity of H-3-PA binding to uptake sites) and B(max) (maximum number of H-3-PA binding sites) of H-3-PA binding were significantly decreased in PTSD patients as compared to normal controls. However, there was no difference in K(d) or, B(max) between PTSD patients with and without a diagnosis of major depression. The B(max) of H-3-PA binding was negatively correlated with state dependent anxiety score whereas K(d) was positively correlated with the Mississippi Scale for Combat-Related PTSD score. The role of serotonergic processes in the psychobiology of PTSD is discussed.