Lack of specificity of reduced platelet imipramine binding in different psychiatric conditions

We compared 3H-imipramine binding in 10 major depressives with that in 29 healthy volunteers, 13 patients with panic disorder, 9 patients with bulimia, 9 suicide attempters, and 6 schizophrenic patients. None of the comparison groups had histories of major mood disorders, except the suicide attempters. We found a significant reduction of the maximum binding capacity (Bmax) in all groups of patients as compared with healthy controls. These data cast doubt upon the specificity of the decrease of platelet 3H-imipramine binding in major depression, but suggest a possible pharmacological common denominator involving the serotonin system.