Platelet α 2-adrenoceptors in major depression: relationship with urinary 4-hydroxy -3- methoxyphenylglycol and age at onset

Abstract

Platelet α 2-adrenoceptor number and affinity were measured in 31 drug-free patients with major depressive illness utilizing 3H-clonidine as ligand. A significant negative correlation was found between number of α 2-adrenoceptors, baseline urinary 4-hydroxy-3- methoxyphenylglycol (MHPG) excretion, present age and age at onset of the disease. K d did not correlate with any of these variables nor with the B max of platelet α 2-adrenergic binding. Multiple regression analysis, with MHPG and age at onset as independent variables, explained variance for α 2-adrenoceptor density better than single regression (from 19% for MHPG and 30% for age at onset to 40%), with the addition of both these variables being significant.