A tiny molecule may help battle depression

June 8, 2014
This is a sample from the Douglas-Bell Canada Brain. Credit: Douglas Institute

Levels of a small molecule found only in humans and in other primates are lower in the brains of depressed individuals, according to researchers at McGill University and the Douglas Institute. This discovery may hold a key to improving treatment options for those who suffer from depression.

Depression is a common cause of disability, and while viable medications exist to treat it, finding the right medication for individual patients often amounts to trial and error for the physician. In a new study published in the journal Nature Medicine, Dr. Gustavo Turecki, a psychiatrist at the Douglas and professor in the Faculty of Medicine, Department of Psychiatry at McGill, together with his team, discovered that the levels of a , miR-1202, may provide a marker for depression and help detect individuals who are likely to respond to .

"Using samples from the Douglas Bell-Canada Brain Bank, we examined brain tissues from individuals who were depressed and compared them with brain tissues from psychiatrically healthy individuals, says Turecki, who is also Director of the McGill Group for Suicide Studies, "We identified this molecule, a microRNA known as miR-1202, only found in humans and primates and discovered that it regulates an important receptor of the neurotransmitter glutamate".

The team conducted a number of experiments that showed that antidepressants change the levels of this microRNA. "In our clinical trials with living depressed individuals treated with citalopram, a commonly prescribed antidepressant, we found lower levels in depressed individuals compared to the non- before ," says Turecki. "Clearly, microRNA miR-1202 increased as the treatment worked and individuals no longer felt depressed."

Antidepressant drugs are the most common treatment for depressive episodes, and are among the most prescribed medications in North America. "Although antidepressants are clearly effective, there is variability in how individuals respond to antidepressant treatment," says Turecki, "We found that miR-1202 is different in individuals with depression and particularly, among those patients who eventually will respond to antidepressant treatment".

The discovery may provide "a potential target for the development of new and more effective antidepressant treatments," he adds.

Explore further: Biomarkers for antidepressant treatment response

More information: miR-1202 is a primate-specific and brain-enriched microRNA involved in major depression and antidepressant treatment, Nature Medicine, DOI: 10.1038/nm.3582

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7 comments

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JVK
1.6 / 5 (7) Jun 08, 2014
Each time you see information like this reported:

1) "Levels of a small molecule found only in humans and in other primates are lower in the brains of depressed individuals..."

2) "...antidepressants change the levels of this microRNA."

-- ask yourself why evolutionary theorists have been unable to grasp the fact that conserved molecular mechanisms are involved in cell type differentiation, which means the nutrient-dependent microRNA/messenger RNA balance must be involved and that mutations are not involved in increasing organismal complexity and biodiversity.

It's a simple concept. All organisms must eat, none must mutate.

Let's make it simpler: Food is good for all organisms; mutations are bad.

Evolutionary theorists aren't very bright, are they? Who is teaching your children and grand-children?

Nutrient-dependent/pheromone-controlled adaptive evolution: a model. http://www.ncbi.n...24693353
Captain Stumpy
5 / 5 (4) Jun 09, 2014
All organisms must eat, none must mutate
@jk
so what you are saying then is that your model for diversity is completely out the window, because you say
mutations are bad
but at the same time promote mutations with this
Nutrient-dependent/pheromone-controlled adaptive evolution
no wonder you are considered a pseudoscience crackpot!
I asked
DOES your model make any changes to the nucleotide sequence of the genome of an organism, virus, or extrachromosomal genetic element?
This is a yes or no answer
(this is the definition of mutation) to which you answered
YES!
--Thanks for asking
so, drawing from your own words AGAIN...
IF mutations are BAD
mutations are bad
AND you say yourself that your model causes mutations
YES!
--Thanks for asking
THEN one can only conclude, per your own words and conclusions, that YOU are an IDIOT! and that you don't understand your own model let alone your field!

this is your own logic and in your own words, jk
alfie_null
5 / 5 (3) Jun 09, 2014
Evolutionary theorists aren't very bright, are they? Who is teaching your children and grand-children?

I do believe I'd rather not have the likes of you anywhere near my children and grandchildren. Would you agree you fit the definition of "crank". Do you understand being a crank to be an aberrant mental state?
Surly
2 / 5 (1) Jun 09, 2014
The article's fine, but it's misleading to refer to an miRNA as a "tiny molecule" because miR-1202's still quite a lot larger than most small molecule drugs.
JVK
1 / 5 (4) Jun 09, 2014
http://freethough...s-place/

PZ Myers decided to first label me a "crank" and then -- after 800 blog posts by his idiot minions, he labeled me "homophobe" because it was becoming clear that none of the participants on his blog could make decisions about cause and effect at the level of a microbe.

How do Microbes Make Decisions

http://jonlieffmd...79440661
Sinister1812
not rated yet Jun 09, 2014
They said this was just an indication, right? So how will it lead to a better treatment?
JVK
1 / 5 (4) Jun 09, 2014
Nutrient stress and social stress epigenetically effect the same central neuronal system in all vertebrates (i.e., the GnRH neuronal system). It is altered by changes in the nutrient-dependent microRNA/messenger RNA balance.

Understanding how that balance links the epigenetic landscape to the physical landscape of DNA via alternative splicings of pre-mRNA, amino acid substitutions, and cell type differentiation will lead to better treatments for all disorders of cell type differentiation, not just the disorders commonly treated with antidepressants.

Researchers from Israel are consistently making the most scientific progress in this context, probably because the schools in Israel do not teach children to believe in the pseudoscientific nonsense of neo-Darwinism. In fact, the decision was made to begin teaching the theory of evolution so that it could be compared to what's scientifically known about ecological variation and ecological adaptation.

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