[Biochemical aspects of depression (author's transl)].Sem Hop 1981 Apr 18-25; 57(15-16):745-50SH
Alterations of brain monoamines in animals produced by antidepressant administration suggest that depression may involve these monoamine systems. In an attempt to examine these possibilities, investigations of central noradrenergic and serotoninergic metabolism in depressed patients were performed but at times these have failed to produce convincing results. The exact mechanism of action of antidepressants remains also unknown. Nevertheless recent findings show that chronic treatment induces changes in the sensitivity of the beta-noradrenergic and serotoninergic receptors closely correlated in time with clinical improvement and common to all types of antidepressant drugs. Tricyclic anti-depressants also act directly as antagonists on alpha-adrenergic, cholinergic and H1, and H2 histaminergic receptors and it has been assumed that these pharmacological properties account for the side-effects of these drugs. Recently, high affinity binding sites for 3H-imipramine were demonstrated, the significance of which is still unresolved.