
Link Between Neanderthal DNA and Depression Risk - diodorus
http://www.theatlantic.com/science/archive/2016/02/neanderthal-dna-affects-depression-risk-today/462345?single_page=true
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tbabb
> the effect is subtle, explaining just 1 percent of a person’s depression
> risk.

That seems like noise to me. Especially in such a large study that attempted
to cross-correlate (apparently) hundreds of factors, I would require a _lot_
more evidence not to discard this as the jelly bean effect
([https://xkcd.com/882/](https://xkcd.com/882/)).

Now I haven't read the paper, but based on this article, I dare say it would
be irresponsible to label this a finding.

~~~
azakai
In addition, even if there is a real effect here, it is so small, and the
interactions so complex, that it's probably useless.

For example, even if this neanderthal gene happens to causally affect
depression by 1%, that pathway might be something like

gene => slightly wider shoulders => that body structure is slightly more or
less likely to lead to certain life outcomes, like marrying early or getting
promoted or getting targeted by pickpockets => change in depression risk

As a result, the gene might currently lead to a 1% increase in depression
risk, but in a few years it might do the opposite, if things change in the
surrounding culture and those intermediary steps behave a little differently.

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kordless
> Some headlines will inevitably claim that we can blame Neanderthals for
> depression, but that’s nonsense.

Says the article titled _Link Between Neanderthal DNA and Depression Risk_.

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Scaevolus
"They started with 13,700 people from the eMERGE Network, and looked for
associations between 135,000 Neanderthal genetic variants and 1,689 different
traits."

Does anyone know how they compensated the statistics to control for the
p-hacking?

~~~
adenadel
I took a brief look at the paper scanning for multiple hypothesis testing
corrections.

"Neandertal variants have been hypothesized to influence many phenotypes in
AMHs, including lipid metabolism, immunity, depression, digestion, hair, and
skin, on the basis of the enrichment of Neandertal variants in regions of the
genome relevant to these traits. Accordingly, we first tested these hypotheses
using genome-wide complex trait analysis (GCTA) to estimate the phenotypic
risk explained by 1495 genotyped common (minor allele frequency > 1%)
Neandertal SNPs for a set of 46 highprevalence phenotypes from the
hypothesized categories, using age, sex, and eMERGE site as covariates."

When testing these 46 traits they controlled the FDR < 0.05 (false discovery
rate). Then they replicated the associations in an independent sample.

The effect sizes are pretty small (1-2%), so having the explanatory variants
won't have much bearing whether or not you'll get these complex traits.

~~~
nerdponx
Was the _only_ correlation that survived FDR control and the validation set?

I'm also curious as to why ethnic origin wasn't a covariate.

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redsummer
Even Darwin had noticed this, when he described the differences between groups
which (unbeknownst to him) had Neadenthal origins and those who don't.

"There is however no doubt that the various races when carefully compared and
measured differ much from each other as in the texture of the hair, the
relative proportions of all parts of the body, the capacity of the lungs the
form, and capacity of the skull, and even in the convolutions of the brain.
But it would be an endless task to specify the numerous points of difference.
The races differ also in constitution in acclimatisation and in liability to
certain diseases. Their mental characteristics are likewise very distinct
chiefly as it would appear in their emotional but partly in their intellectual
faculties. Every one who has had the opportunity of comparison must have been
struck with the contrast between the taciturn, even morose, aborigines of S.
America and the light-hearted talkative negroes."

And to think, some fundamentalists want to ban discussion of Darwinian
evolution.

~~~
big_surprise
You'll be depressed too... Once the transhumanists are successful in their
plot to rule the entire planet, while they constantly insist on using "Homo
Sapien Sapiens" as a colloquial derogatory term for "those intellectually-
challenged violent brutes" ;)

