Dopamine/dopaminergic system depression

Altered dopaminergic system function has been implicated in major depression. Patients with major depression have been reported to have lower CSF levels of the dopamine metabolite homovanillic acid (HVA) compared to nondepressed controls, with more severely depressed patients having still lower CSF HVA levels (see [42] for a... 

Willner (1995) provides evidence from many sources that increases or decreases of dopaminergic activity in the mesolimbic system may underpin the pathophysiology of mania and depression respectively. A key area involved may be the subgenual prefrontal cortex which receives extensive reciprocal dopaminergic projections from the ventral tegmental area and substantia nigra and influences dopamine release in the nucleus accumbens (Drevets et al., 1997 see Chapter 16). 

None of the TCAs seem to have an effect on dopaminergic neurotransmission in the central nervous system (CNS). This has been supported by the lack of alterations in dopamine receptor sensitivity in chronically treated patients who have shown response to treatment (Sugrue, 1983). More recent investigations have also shown that administration of DMI to depressed subjects had no effect on levels of homovanillic acid, the principal metabolite of dopamine, in a measure of brain neurotransmitter production. In this investigation, DMI administration did increase norepinephrine production and overall cerebral metabolism (Lambert, 2000). 

---