
No person who was born blind has ever been diagnosed with schizophrenia - SZJX
https://www.vice.com/en_us/article/939qbz/people-born-blind-are-mysteriously-protected-from-schizophrenia
======
Retric
If you’re wondering about how common this should be:

 _if schizophrenia occurs at a rate of 0.72% in the population (McGrath et
al., 2008) and congenital blindness occurs at an estimated rate of 0.03% in
people born in the 1970s and 1980s (based on Robinson et al., 1987), then the
joint probability of a person having both conditions, if the two are
independent, would be 0.02% or 2 out of every 10,000. Although this is a low
prevalence rate, it is higher than the rates for childhood-onset schizophrenia
(Remschmidt and Theisen, 2005), and many other well-known medical conditions
(e.g., Hodgkin 's lymphoma, Prader Willi syndrome, Rett's Syndome). Based on
this estimated prevalence rate, in the United States alone (with a population
of 311, 591, 917, as of July 2011, according the US census), there should be
approximately 620 congenitally blind people with schizophrenia._
[https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3615184/](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3615184/)

That does do rule out misdiagnosis etc, but it does seem to support a
correlation.

~~~
prostheticvamp
Just so we are clear: the approach taken in the studies described is “we
looked at a bunch of blind people and couldn’t find a schizophrenic”, and “we
looked at a bunch of schizophrenics and couldn’t find a blind person.”

The appropriate question is: can such an approach, in a wildly fractured
series of data sets, overlook 600 people?

~~~
Uhhrrr
It sure can, but the odds are against it overlooking all of them.

Of course, maybe the genes leading to blindness and schizophrenia together
also lead to some other defect that results in miscarriage or some other kind
of early death.

~~~
ajross
To be clear: the odds are against it _assuming no confounding interference_.
And given that, I don't know that an error of 600 is really that much of a
statement. I mean, just to invent an example (not the only possible one,
obviously!):

Congenital blindness is likely diagnosed with near 100% certainty in early
childhood. It's easy to spot. The same is very much NOT true of mental health
problems. Schisophrenics are diagnosed, almost always, when their condition
manifests in such a way to interfere with their life (or someone else's) to
the extent that the doctors get called in. There are widely assumed to be LOTS
of undiagnosed mental health cases in society, simply because the sufferers
live in situations where their disorder can be managed (or suppressed!) in an
ad hoc way.

Now, the question becomes: are blind people more likely to be living in a
circumstance where their mental health troubles are more easily
managed/ignored/suppressed without the involvement of doctors who would
otherwise diagnose schizophrenia? That seems not at all unlikely to me.

And frankly: this kind of confounded measurement strikes me as MUCH MORE
likely than a heretofore unrecognized link between vision and schizophrenia.
Significant results require significant proof, and I don't think this is it.

~~~
wpietri
> are blind people more likely to be living in a circumstance where their
> mental health troubles are more easily managed/ignored/suppressed without
> the involvement of doctors who would otherwise diagnose schizophrenia? That
> seems not at all unlikely to me.

Could you explain your thinking to me? I'd think that people with one serious
condition would me much more likely to have a second serious condition
diagnosed, purely because of increased attention from medical professionals.
That's certainly been my experience.

~~~
skat20phys
The issue is that psychosis/schizophrenia isn't like testing for a bacterium
or looking at an x-ray. It's really a label for a set of presenting behavioral
patterns, and is heterogeneous (I don't mean this critically, just the way it
is).

So let's say someone is blind, and they come in. They will almost certainly be
more likely to receive attention than someone who is not. But how their
presenting disorganized thoughts, etc. are described is likely to be different
given their history of blindness, especially if they had a lifetime history of
associated cognitive deficits or issues.

It's also the case that overlapping presence of two pathologies is not
necessarily same as them disjointly. So blindness etiological factors +
psychosis etiological factors may not equal schizophrenia with blindness, but
rather a more severe cognitive and/or physical disorder that receives an
entirely different diagnosis. This latter scenario isn't necessarily a
measurement issue, but it could be construed that way.

~~~
Mirioron
> _But how their presenting disorganized thoughts, etc. are described is
> likely to be different given their history of blindness, especially if they
> had a lifetime history of associated cognitive deficits or issues._

Another thing to consider is that a lot of people with mental illness can tell
something is wrong with them because they can compare themselves to others.
It's much harder for a blind person to do that because they don't get a lot of
the information most people get passively by simply being near other humans.

I have (untreated) asthma, but nobody ever explained to me what having asthma
means. I was well into my adulthood before I found out that it is not normal
to have difficulty breathing hours and sometimes days after simple aerobic
activities. And I didn't even have the issue that I couldn't see that other
people didn't have this issue. I just thought that this was normal and they
were better trained.

------
stef25
Very interesting. I wonder if there's a link between melatonin production in
the pineal gland (affected by visual perceptions of light) and endogenous DMT,
also suspected of being produced in the pineal (see Rick Strassman's work)

For a long time endogenous DMT, or some other endogenous psychoactive
compound, was suspected of being a cause of schizophrenia. I think it's
largely discredited by now anyway.

~~~
andai
The endogenous psychoactive idea is fascinating. My friend called me during a
psychosis, and I was convinced he was having a really bad psilocybin trip.

~~~
dcolkitt
Modern research has actually found closer ties between psychosis and a
different psychoactive compound: dynorphin[1]. In terms of recreational drugs,
this is the neurotransmitter responsible for a salvia trip.

From an outside standpoint, this makes more sense than the classical
psychedelics. Unlike LSD or psilocybin, salvia hallucinations usually result
in a total disconnect from reality, and the user is often rendered catatonic
like in severe cases of schizophrenia.

[1]
[https://www.sciencedirect.com/science/article/pii/S000632231...](https://www.sciencedirect.com/science/article/pii/S0006322319313794)

~~~
koboll
I remember some of the first time I did salvia. I was sitting on a couch at
the end of a room, and I looked up at the corner of the ceiling, where the
ceiling met two walls. Then I looked back at the people I was sitting with,
but all I could see was the corner of the ceiling, where the ceiling met two
walls. Then after... seconds? A minute? An hour? I could see normally again,
but the room I was in began to move backward. It detached from an enormous
wall, where it was revealed to be one of an infinite grid of identical rooms.

I don't remember the rest. Apparently all I did the whole time was stare with
a blank expression for five minutes.

Salvia. It's powerful stuff!

------
drcode
I think the vast majority of schizophrenics have relatively mild symptoms
(just as most diseases have more sufferers of a mild version vs. more severe
version) and their diagnosis is made primarily because they have a disease
that makes it hard for them to be 100% self sufficient, and there needs to be
a paper trail in place that documents this.

Although the majority of blind people have essentially 100% self sufficiency
(maybe with some occasional help from family/friends on some edge cases) I
suspect it is relatively easy for a congenitally blind person to get financial
and other assistance in the US, since as a society we are fairly supportive of
people with obvious congenital disabilities. I could therefore imagine that if
there was mild schizophrenia in a congenitally blind person, there'd be far
less incentive for the affected person or their family to establish a formal
diagnosis to this effect.

I wonder if this could be a partial explanation for this surprising statistic
(and the lack of evidence for severe schizophrenia could maybe just be due to
inadequate sample sizes in the OP study to detect this smaller set of people.)

------
meroes
Maybe the visual center has more trust over auditory or other parts of the
brain? For example an auditory hallucination is easily discounted, but if most
people witnessed a visual hallucination, they'd question their own sanity
because that signal is so trustworthy? There's many other explanations just a
random thought.

~~~
K0SM0S
It's an interesting thought. I wonder if the nature of schizophrenia isn't
particularly conducive (almost binarily so) to being "driven" by visual
signals.

In my interactions with schizophrenic people (especially when untreated), I've
witnessed intense and unusual attention (some would say obsession) devoted to
"patterns" — I've no other word to describe it generally; to paraphrase it:
"order or regularity in visual, typically geometric or symbolic sequences of
objects", a particular fascination for certain shapes or symbols.

Somehow, at some point in the processing, said patterns acquire additional
meaning, what I'd call uncanny connections. (Schizophrenic people deeply
believe that they see how to "connect the dots" — hence a particular tendency
for tinfoil hatism and other paranoid world views.)

It also seems to work with music and other sensory inputs, though, but as you
said, it could be that the visual is beyond some threshold, or of a particular
nature so as to be able to trigger the schizophrenic patterns.

There's also this history of violence with the onset of schizophrenia, it
seems to be an acquired condition notably highly correlated with childhood
suffering (of abnormal magnitude and length), but with possibly typical
genetic or epigenetic predispositions. This tells us again to search for a
trigger, and it's interesting that people born blind never seem to experience
such a triggering, the onset of schizophrenia, ever.

But people born blind are also different in many other ways, biologically —
notably circadian rythms, etc. I should know because although I'm perfectly
able to see I experience a few but too many of the same kind of second- and
third-order conditions that blind people have, and that led me to suspect it
was related to a deficiency of mine in regions of the brain related to the
processing of light in relation to time (cycles of melatonin, hunger, etc;
iirc it's generally involving the thalamus).

I don't really know what conclusion to make of all this, but I feel these are
clues, help narrow or focus the solution space.

~~~
hi41
I am able to relate to your comment about patterns. I have had two episodes of
anxiety attacks. I had visual hallucinations that kept repeating and wouldn’t
stop. It was absolutely horrible. When the anxiety attacks used to happen I
would stare at the wall for long durations. The wall had bricks in brown and
white. I did not like that there was no symmetry. I kept repeating over and
over that the wall lacked symmetry. I also experienced myself and my thinking
self as two different entities and it as if I could watch myself as another
person.

Edit: added the last sentence.

~~~
K0SM0S
I think I can relate to your experience, from similar anxiety moments under
some cocktail of sustances (alcohol and weed for me in my youth).

> I also experienced myself and my thinking self as two different entities and
> it as if I could watch myself as another person.

Can you expand on this? How was it different from the "third-person" kinda
view that we do casually?

~~~
hi41
Until I experienced, I did know that such a thing existed. After the panic
attack I searched about and found an entire Wikipedia article describing it.

[https://en.wikipedia.org/wiki/Depersonalization](https://en.wikipedia.org/wiki/Depersonalization)

To your question, I think third person view is like an intellectual activity
that one undertake voluntarily. However what I experienced was very real
feelings of separation and not an intellectual role play.

~~~
K0SM0S
Ok, gotcha, not an intellectual role play.

I think we all dissociate, like it's a spectrum; the weakest most minute
manifestation is when we just 'take a step outside of our current state' you
know, when you stretch just a bit to be/think/do slightly different.
Experiment. Mimicry. We temporarily sever/disable a few 'links' inside and let
new connections form, just to see.

It's also how I picture resisting empathy, all these times when we shut down
feelings almost automatically — some of it is mundane 'keep a straight face',
some of it is deeply atrocious like awful news or misery right in front of
you. We have these "mirror neurons" that automatically replicate emotions of
those we see¹; and unless we shut it down or temper it, we are bound to feel
that very thing too. I think we kinda "dissociate" mildly from these mirrored
feelings whenever we must, it's automatic by now (social species must do that
to evolve beyond primal emotions it would seem).

But sometimes dissociation gets out of hand, cranked up to 11, and it operates
versus parts of your own self, it shuts down entire regions of our inner
world, and what's left to see is a weird, paradoxical state, that which
psychology and the DSM see and would rightfully call pathological etc.

____

[1]: _That got me thinking, maybe it 's one thing people born blind can't do:
"see" the emotions of others and trigger mirror neurons in that way. Maybe
there's something in this, in the unsufferable realization that you may see
but never really know what's inside others, that drives schizophrenic people
so obsessed whereas blind people, obviously, can never experience such a
feeling. It certainly converts to other senses (voice conveys so much emotion
for instance), but hypothetically very differently. I don't know. Thinking out
loud here._

------
rezgi
Isn't it that when you combine two extremely low prevalence phenomenons
together, you can't really make any accurate predictions because the numbers
are so low that the error margin is too high? I might be wrong, but I seem to
remember something to that effect. Could it be what's at play here?

~~~
K0SM0S
The thing is, if you had a discrepancy of some order of magnitude (e.g. 6,000
or 60 instead of 600), you could talk about accuracy problems. You could look
into rounding errors and margins of errors, like we do with constants in
physics, and that would maybe yield some new or modified equations (models).

But the "binary" _absence_ of even 1 single case hints at something else: it's
a category thing, there's "in it" or "out of it", and it seems that being born
blind somehow means you can't develop schizophrenia.

~~~
contravariant
The absence of any cases is strong evidence against the null hypothesis that
the both are independent (assuming the combination isn't just much harder to
diagnose), but it _isn 't_ strong evidence for it being impossible. Just
because something hasn't happened doesn't allow you to distinguish between it
being impossible and it being very unlikely (of course the other way around
does work, then this is strong evidence that it is possible).

~~~
K0SM0S
I will yield to your logic, and thanks for taking the time to explain how my
approximation was flawed. I really need to brush up my logic skills... I did
say "hint" though, which really means it is hypothesis, not strict logic at
that point.

Edit: wait, no, I re-read my post and clearly, I did not make the logical
fallacy. You're correct, and I did see that, hence using the word "hints at",
not "means that". But my wording was bad afterwards ("is" instead of "would
be"). : ) so thanks for clarifying.

------
Amygaz
That paper suffers from a small number problem.

With simple probability, using their 0.4%, it means that you would expect 0.26
blind child out of 66 to have schizophrenia. So that they see 0 is perfectly
reasonable. For the other psychotic illness, that probability is 1.5%. So, out
of 66 you would have expected 0.99. Maybe that kid is the lot and will develop
apparent symptoms of psychosis in the next few years...

In general, an epidemiology study without statistic means that they try to
find something but they didn't and couldn't explain why.

Now, common epidemiology statistic are going to use a 5% alpha error and a 95%
confidence. So, if they were to repeat that experiment a 100 times, 95 times
you would observe a value close to the mean. The probability numbers given are
maximum, and I would guess that the minimum is zero. So 95% of the time, you
would have a value much lower, and closer to zero individuals out 66 for
psychosis.

------
orblivion
Even if there's some sort of genetic or environmental barrier, you would think
that it would happen at least once as a misdiagnosis.

------
growlist
From my admittedly completely uninformed position, this looks so much like
academics searching for some profound insight that will win a Nobel prize (or
perhaps just guarantee a tasty stream of research grants) when in reality the
truth could be much simpler. Let's look at an example of a group that suffers
disproportionately:

'The high level of schizophrenia in black Caribbeans living in the UK probably
reflects the interaction of multiple risk factors, many of which cluster in
the black Caribbean community in the UK. Particularly significant factors
appear to be the combination of isolation and exclusion, both within society
(living in areas of low ethnic density and reduced participation in society)
and within the family (family break-up and paternal separation). These factors
seem to be more powerful than socioeconomic disadvantage, which is more likely
to be a consequence than causal. Racism itself may contribute to social
exclusion, increasing the vulnerability to schizophrenia. Biological or
genetic susceptibility do not appear to explain high rates of schizophrenia in
black Caribbeans. More research is needed about the role of cannabis,
particularly in its more potent forms, and whether this contributes to the
excess of schizophrenia in black Caribbeans.'

Perhaps it's as simple as: people that are born blind are to some extent
insulated from risk factors that are conducive of schizophrenia.

[https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2418996/](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2418996/)
(just the first article I could pull up on a phenomenon I was aware of)

~~~
ramraj07
With regards to being skeptical of scientists and their motivations, I m as
myopic as they come, but even to me this is a stretch. This is a legitimately
interesting observation, something that does make sense given how big a role
our visual cortex plays in the brain. You're right that there are risk factors
but they just increase and decrease frequencies. If a factor eliminated this
condition, there's definitely need to investigate that further to understand
why.

------
pattisapu
I wonder if this points to the problems in the concept of this diagnosis.

It has been seriously questioned since World War II as to whether
schizophrenia is even a disease.

The questioners being mostly from the psychoanalytic school (some
psychiatrists), all forgotten, may have something to do with it.

In my family more than half of one side of my immediate parent-generation
family members have been diagnosed with the disease. Most of them get by with
little to no drugs.

All of them were diagnosed in connection with divorce proceedings.

(We had a misunderstanding. You must be hearing voices.)

I could not help but believe, admittedly biased, that this is "health" as a
locus of power, blame, and control.

In higher education I had close blind friends who achieved high marks and went
on to work in Fortune 500 companies, at a level not unlike people I knew
before they got hit with a diagnosis. Did they have disagreements with loved
ones? Sure. If they had found themselves in a bitter marriage and divorce,
would something they said be weaponized into a diagnosis of mental illness?
Maybe. At the rate of the general population? Maybe. I don't know.

I am not criticizing, accosting, or accusing anybody of anything. Just asking
some questions.

------
INTPenis
So what does that imply? That visual sensory input might trigger
schizophrenia? But that would imply that blind people have diminished sensory
input. I just don't buy that.

They have a lot of sensory input, perhaps as much as seeing people. It's just
delivered differently. Try an isolation tank. I can totally imagine someone
going crazy in one of those.

The original title was even more click-bait. I'm glad it was changed before
posted here.

~~~
pazimzadeh
Light inhibits melatonin release.
[https://en.wikipedia.org/wiki/File:Circadian_rhythm.svg](https://en.wikipedia.org/wiki/File:Circadian_rhythm.svg)

Low melatonin levels are correlated with many diseases, including cancer and
schizophrenia.

> The results indicated that blind women had a 35% reduced risk of developing
> breast cancer. Moreover, women who became totally blind prior to age 65 had
> a 50% reduced risk [https://news.cancerconnect.com/breast-cancer/blind-
> women-hav...](https://news.cancerconnect.com/breast-cancer/blind-women-have-
> lower-risk-for-breast-cancer-NpAaFuxgUE2jHxY1UxDiJw)

Role of Melatonin in Schizophrenia
[https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3676771/](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3676771/)

Disappointing that the article doesn't mention melatonin once.

~~~
6nf
Do blind people get less light?

~~~
pazimzadeh
Less light in the retina, yes. But there are different types of "blind."

~~~
6nf
So at least some blind people would be unaffected by melatonin differences
which means you should still be able to find blind schizophrenia cases if the
melanonin hypothesis is true

~~~
pazimzadeh
No, they specifically only mentioned people that were "born blind." I was
answering your question:

> Do blind people get less light?

Yes, in their retina. But if you want to be technical, blind people 'get' as
much light as anyone else on the rest of their body.

~~~
6nf
Some people born blind will still get the same amount of melatonin as sighted
people. Therefore you should still see born blind schitzos. But we do not. The
melatonin hypothesis is bunk.

------
oxymoran
What if we could “reboot” a schizophrenic brain through some sort of sensory
deprivation?

~~~
andai
I recently started going to a spa that has float tanks. It's the most relaxing
thing in the world, and I highly recommend it.

While floating, the body is able to relax completely, and this has a profound
effect on the mind. It really does feel like a reboot.

~~~
newshorts
I did one and was completely angry the entire afternoon after.

I think I relaxed so much my body had to rebound to my normal state of
frustration and anxiety.

~~~
kempbellt
Laying in a salt bath can also dehydrate you, a lot.

I've felt particularly grumpy after a float session a couple of times and was
able to remedy this by rehydrating.

------
aiCeivi9
Does aphantasia have any impact?

~~~
Jugglerofworlds
I have aphantasia and schizophrenia. I've never had a visual or auditory
hallucination, but I have had plenty of delusions and cognitive dysfunction.
Ever since learning about aphantasia I've wondered if it has protected me from
these types of hallucinations. Maybe someone should run a study on this?

A common post among the people over at /r/schizophrenia is that the so called
negative symptoms of schizophrenia (anhedonia, apathy, reduced social drive,
cognitive impairment, etc) are just as bad if not worse than the positive
symptoms (hallucinations and delusions). Unfortunately the negative symptoms
are not adequately treated by any medicine and are in fact made worse (!) by
medication. This is probably the number one reason why schizophrenics quit
their medication - the medications are simply so shitty that people would
rather risk the positive symptoms than experience worse negative symptoms.

There's no good research directions for new schizophrenia medications either.
Schizophrenia research certainly isn't discussed (or have funds raised for it)
as much as Alzheimer's research despite the fact that 3.5 million people in
the US have it, and it affects people at a much younger age.

Edit: Before starting medication I noticed some visual disturbances related to
schizophrenia often known as sensory gating deficits. I would get an overload
of visual sensory information to the point where I would notice nearly every
detail in my visual range simultaneously (that's the best way I can explain
it). At times it was actually quite beautiful since the whole world would pop
out in vivid color. However as soon as motion was introduced it quickly became
overwhelming.

~~~
throwa20200212
I have aphantasia and auditory hallucinations.

~~~
mbreedlove
That would mean that you sometimes hear things in your head, but you have no
control over what you hear?

------
caetris1
Schizophrenia is a grouping of symptoms that are generalized to an inability
for a person to smoothly track reality. For example, when a person without
schizophrenia attempts to track the trajectory of an object, the eyeballs
follow a smooth path. When a person with schizophrenia attempts the same, the
eyeballs do not follow a smooth path, with the focal point moving chaotically
off center from the target. A part of the diagnostic criteria for
schizophrenia is testing whether or not the eye can smoothly track the
movement of an object. This would likely be why it is difficult to diagnose
someone that was born blind.

[https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3212396/](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3212396/)

------
8bitsrule
Just speculating, but being born blind has (in recent history at least) led to
a quite sheltered and protected life. For those cases caused by 'chemical
imbalances' (genetic factors), 'sheltering' would not help. For cases that
occur in response to the external world (environmental factors), the
'sheltering' might have a shielding effect.

If so, then the not-blind vulnerable should avoid stress.

------
0xcafecafe
Interesting. Can it also have something to do with an extremely small sample
size? These are both rare conditions so intersection might be even rarer.

~~~
dotancohen
Commenter above addresses this. Considering the prevalence of each condition,
if they were independent then we would expect that 2 out of 10,000 people
should have both together. The fact that zero cases have been found suggests
that there is either a diagnosis issue, or that the two conditions are not
independent.

~~~
klodolph
That was an arithmetic error. It’s 2 out of 1,000,000.

~~~
archi42
The total 620 is actually correct again: 0.0072 times 0.0003 times 311591917
is 673.04. I suppose the 53 person discrepancy is due to rounding towards
0.03% but using a more accurate number for the actual computation (e.g.
0.0277%).

~~~
klodolph
You can’t just throw extra digits around like that. It’s a bit unusual and
jarring to see the population of the US quoted as “311591917” even if that is
the census figure, because such a high-precision number would only be true for
about a minute and you don’t know _which minute._

~~~
archi42
Chill please. I used the exact number from the paper as quoted somewhere else
in this discussion. Which seems adequate when saying that the authors final
number (sixhundredsomething) is most likely correct even if the intermediate
value "0.02%" is obviously wrong (and probably just a mistake in the print).

If you have questions as to which point in time this number refers to, I
kindly refer you to the original paper and/or the authors.

~~~
klodolph
No need to be rude. Sig figs are important, I reworded the comment a couple
different ways to make the comment polite, and I’d appreciate the same
courtesy. The use of an exact number for the US population is not justifiable,
whether you can cite the source for it is not germane.

------
cozzyd
Many antipsychotics are also used as anti-seizure medicines. Seizures are
often induced by visual stimuli. The brain is weird.

------
tidenly
Hearing voices in your head without having sight to confirm if anyone's
actually there or not sounds actually terrifying.

------
tsukurimashou
I would like to hear more about that, about other mental illnesses, depression
etc... Does being blind also affect these?

~~~
dcolkitt
Congenital blind people have much higher rates of autism.

Some models of psychiatric illness view schizophrenia and autism as two
broadly opposite poles of a grand spectrum, so this kind of makes sense in the
context.

~~~
caleb-allen
Do you have any further resources for this view? I'm very interested.

I have an uncle with severe schizophrenia, and a cousin with autism, and just
recently noted in my journal how autism and schizophrenia seem to be the
extremes of one's ability to reason about and categorize the world around
them.

~~~
dcolkitt
SlateStarCodex did a good job covering the high-level evidence for the view:

[https://slatestarcodex.com/2018/12/11/diametrical-model-
of-a...](https://slatestarcodex.com/2018/12/11/diametrical-model-of-autism-
and-schizophrenia/)

------
mantap
It seems intuitive to me that visual centers of the brain don't develop
properly in the absence of visual stimulation. Has anybody done fMRIs to
compare congenitally blind people with those who became blind later in life?
Also it begs the question: which blind person with schizophrenia became blind
at the youngest age?

~~~
azeirah
Schizophrenia is not limited to visual hallucinations though, interesting ;o

~~~
1_over_n
it would be interesting to know if anyone has compared activity in visual
cortex in schizophrenics having auditory vs visual vs olfactory vs tactile
hallucinations to controls.

A quick search shows "hyperconnectivity" has been found betwen the amygdala
and visual cortex in those with visual hallucinations.

[https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4266287/](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4266287/)

------
kazagistar
What's the chance that any two low probability unrelated conditions happen to
have an empty overlap at random?

------
banads
Marshall Mcluhan hypothesized that schizophrenia may be a consequence of
literacy

~~~
djsumdog
Blind people can read though. Many who are born blind learn to read and type
Braille. So it would have to be specifically about visual literacy?

~~~
banads
Indeed, the written word is a purely visual medium, whereas braille is tactile

~~~
r4ltman
It's so refreshing to witness a succinct & perceptive thread, the tactility is
the key

------
kingkawn
It may only be that what we consider to be schizophrenia in a physiologic
sense presents entirely different in the blind and is unrecognizable despite
being present.

------
turowicz
Correlation doesn't mean causation.

------
ptah
This reminds me of a Sandra bullock movie

------
aj-4
Not sure if this will get buried, but I have an anecdote to support the visual
link, which may also help anyone dealing with psychic issues.

I was 23, living abroad, feeling totally isolated.

One day, I smoked weed which led to an "episode" I guess you could say --
quite literally I was hallucinating that I was in a hospital, while i was in
my room.

What happened next was weird. I felt extremely depersonalized for weeks and
months after, concurrently I developed a swirling blind spot in my right eye.

A distortion, so to speak.

I saw neurologists and was diagnosed as having an "ocular migraine" however I
never had a headache so this didn't add up.

Looking back, I believe I was on the brink of becoming schizophrenic - and
would have unless what happened next did.

So this next part is slightly controversial -- but hear me out

Through the several months that would follow I would discover and get obsessed
with "RSD" \-- a controversial company that teaches guys how to pick up girls.

On the surface, it sounds crass and not politically correct, but if you watch
their videos "get you in the door" with "game", and teach you topics of
incredible value, like "growth mindset", "the power of now" / meditation and
believing in abundance.

Now WTF does this have to do with the topic at hand?

Well, being receptive to these new ideas and absorbing them completely changed
my world view.

I grew up in an extremely liberal household, and did feel any agency to affect
the world around me. Fixed mind set.

What these guys gave me was empowerment, agency, a more conservative mindset
under which the world "made sense" \- there was now a framework for reality,
rather than chaos.

Subsequently, I was able to learn programming from scratch, start a business,
go on to make 6 figures less than a year later.

Somewhere along the line the distortion and negative feeling were entirely
replaced. I couldn't tell you when.

tl;dr: I was close to schizophrenia which manifested itself in visual
symptoms, overcame with a mindset change

~~~
aj-4
Follow up: I know it seems crazy and hate to make it political but there is
data to back this up...

[https://twitter.com/phl43/status/1227343129696702468/photo/1](https://twitter.com/phl43/status/1227343129696702468/photo/1)

Try to have an open mind

------
cassowary37
Just queried my health system database and this statement as it pertains to
congenital cortical blindness is factually incorrect.

~~~
eyeundersand
Well, do explain! You can't just say something is incorrect and not elaborate.

~~~
cassowary37
sorry, intended to elaborate: When I query my health system's deidentified
research patient data registry, there are multiple individuals with both a
diagnosis of schizophrenia and a diagnosis of congenital (cortical) blindness.
One can of course quibble that claims codes are unreliable (ie, these people
really have different diagnoses), but my real point is that the entire article
is based on a very limited analysis that could readily be refuted with any of
the claims/health registry data sets.... also amusing to see this downvoted,
people on HN don't like to see their pet theories questioned.

------
rafaelvasco
I don't think schizophrenia has any dependence on visual input at all. This is
just a probability problem, since the combined probability of both occurring
is very small, as the separate probabilities are already small; Anyone that
has a brain can have the disease, blind or not; The disease itself is very
little understood. For example, when I was a child I had visions and heard
voices. I would go to sleep and then, in the middle of the night I would wake
up and start seeing things around me, hundreds of voices talking, light
beings, etc. Some would call me a schizophrenic, some a medium. I could be
both, could be neither;

