• N&PD Moderators: Skorpio | someguyontheinternet

Homovanillic Acid Concentrations

Smyth

Bluelighter
Joined
Nov 10, 2004
Messages
2,157
Location
England
There are multiple lines of evidence that provide a compelling rationale for the “addition” of a dopamine component to a dual uptake inhibitor.

1) Both clinical and preclinical findings link anhedonia, a core symptom of depression, to deficits in mesocorticolimbic dopaminergic function.

2) Homovanillic acid concentrations are lower in the cerebrospinal fluid of depressed patients compared to normal individuals.

3) Imaging studies indicate a lower density of striatal dopamine transporters in depressed patients than in controls.

4) Clinical pharmacology, including the findings that dopamine reuptake blockers and dopamine agonists are antidepressant. Further adjunctive use of a dopamine agonist has been reported to augment the effect of “traditional” antidepressants in refractory patients.

5) In preclinical studies, an increased sensitivity of dopamine receptors is among the most consistent changes produced by chronic antidepressant treatments. These effects can be observed at the behavioral, cellular, and molecular levels. It has been hypothesized that the interval required to affect this increased sensitivity of dopamine receptors may contribute to the therapeutic lag common to biogenic-amine based antidepressants. These preclinical findings, together with the evidence that dopamine plays a key role in hedonic processes, indicate that a compound producing an immediate increase in synaptic dopamine concentrations will result in a more rapid onset of relief, shortening or eliminating the therapeutic lag.


Sorry, im too lazy to USFSE atm. Would anybody have the courtesy to explain wtf "Homovanillic acid concentrations" are please? And what there relevence is to dopamine. Regards
 
I don't believe point 2)... not even a little bit. This sounds like schpiel from a drug company.

Homovanillic acid (HVA) is a metabolite of dopamine, the ratio of DA/HVA is a measure of dopamine turn over. The higher the ratio, it is supposed, the less dopamine released (i.e. less turned into HVA). Then it's taken to mean that low HVA means low dopamine release.

To quote from an old review in ANYAS:
Although several studies have demonstrated low concentrations of the serotonin metabolite, 5-hydroxyindoleacetic acid (5-HIAA), and the dopamine metabolite, homovanillic acid (HVA), in depressed patients, these early studies may have been biased by concomitant administration of antidepressant drugs (which tend to lower CSF 5-HIAA), amount of CSF drawn (there is a concentration gradient for both metabolites), and selection of control subjects. Once these methodological details are controlled for, the differences between depressed patients and controls are unimpressive.
 
Top