Was cruisin’ some of my chipur-favorite websites this morning and a headline on medicalnewstoday grabbed my attention. It seems as though scientists at the Queensland Brain Institute (Australia) have uncovered one of the ways in which antidepressants elevate mood. The research was published today in the Journal of Neuroscience.
Okay, let’s set the table before we sit down for the meal. In the mid-20th Century it was discovered that manipulation of a class of neurotransmitters known as the monoamines could have positive impact on mood and anxiety. Serotonin, norepinephrine, epinephrine, and dopamine are monoamines; though serotonin is in a separate sub-class.
So on came the tricyclic antidepressants (TCAs) and the monoamine oxidase inhibitors (MAOIs). And decades later we saw the introduction of the selective serotonin reuptake inhibitors (SSRIs) and the selective serotonin norepinephrine reuptake inhibitors (SSNRIs). Well, with the exception of the SSNRIs serotonin has always been the star player.
That said, its feedback loop relationship with norepinephrine has never been dismissed. See, by design, as serotonin levels are sufficiently maintained, so are levels of norepinephrine. When levels of serotonin run low, levels of norepinephrine increase in an effort to ramp-up serotonin levels. And when serotonin levels, indeed, rise, levels of norepinephrine recede in kind. Can you see this notion of a feedback loop coming into play here?
Bottom-line is, if we can’t maintain sufficient levels of serotonin, and norepinephrine can’t stimulate a boost, obviously the presence of serotonin plummets. And the end result may well be symptoms of depression and anxiety.
So now it’s time to eat. Through their research, our Aussie friends are confirming the clout of norepinephrine. And that’s because they’ve found it encourages neurogenesis (the generation of new neurons) within the hippocampus (a component of our brain’s limbic system huge in long-term memory, emotion, and spatial orientation).
How ‘bout this statement from lead researcher, Dr. Dhanisha Jhaveri? “If you block hippocampus neurogenesis, antidepressants no longer work.” Wow!
Interestingly enough, the study showed medicines that increased levels of serotonin failed to generate neurogenesis. Now, that doesn’t mean manipulation of serotonin levels doesn’t help elevate mood…so don’t call your psychiatrist demanding a change from your SSRI to an SSNRI. It just means more research is indicated to determine why and how the change in mood occurs.
Also of note, the research piqued interest in levels of something known as beta3 adrenergic receptors, and placed the topic on the radar screen for future work.
If you ask me, this is all very exciting news. Okay, so the research was conducted using rodents. And, yes, news of radically new treatment strategies incorporating exotic new medicines wasn’t published today. But, come on, let’s open our minds a bit.
The truth of the matter is this research is incredibly hopeful. And not only because of its content, but because it tells us work is going on right now in an effort to learn why we suffer as we do; and what can be done to bring relief. And that’s a good thing.
So, chipur readers…what are your feelings and thoughts. As always we’d love to have your comments. Won’t you share?