Biological markers in juvenile depression

3H- p-Aminoclonidine binding to platelets of children and adolescnets with major depressive disorder was compared to that of a healthy control population. Significantly higher α 2-adrenoceptor K d and B max values were observed in the patient population. 3H-Dihydroalprenolol binding to lymphocyte membranes of the same patient population showed significantly higher β- adrenoceptor B max values than controls. Control females had significantly higher β-adrenoceptor K d values than control males, and the female patients had significantly lower β-adrenoceptor K d values than control females. 3H- Imipramine binding to platelets of these patients showed significantly higher imipramine K d values in patients with a suicide attempt, whereas the imipramine B max values were significantly increased in patients with major depressive disorder with or without a suicide attempt. We propose that increased platelet α 2-adrenoceptor K d and B max values, together with increased platelet imipramine K d values, may serve as possible biological markers for children and adolescents with major depressive disorder and a tendency toward suicide. Elevated platelet imipramine and lymphocyte β-adrenoceptor B max values may be biological markers for juvenile depression, and decreased β-adrenoceptor K d values may be a biological marker for depression in young females.