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AFAIK twin studies where babies were adopted suggest that schizophrenia is likely to be genetic in causation to a large degree. That doesn't rule out the commo

AFAIK twin studies where babies were adopted suggest that schizophrenia is likely to be genetic in causation to a large degree. That doesn't rule out the common environment of the womb of course.

Nasrudith 8y ago
I thought the nazis proved that it /wasn't/ genetic strongly by murdering nearly every diagnosed schizophrenic under their domain. The rates were unchanged. Maternal nutrition seems far more likely given the prevalence being lowest in wealthier countries and higher in poorer countries on maps. Granted it may technically be epigenetic.
- krageon 8y ago
  All they proved is that murdering all people (that they could find) with schizophrenia doesn't lower the incidence rate of schizophrenia. This paper https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2800142/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2800142/ discusses a few of the reasons why that could be the case, but obviously it doesn't make grand claims.
  - Nasrudith 8y ago
    Interesting that sufficient complexity may also work as a reason. I would have expected some deceease in a genetic context but I suppose sickle cell anemia is another example with simpler structuring given it is partially adaptive and partially maladaptive given one means malaria resistant blood and two means concave red cells bad at their job. Even if malaria vanished a thousand years ago the trait would probably stick around today. Thanks for the link and furthering my understanding. I wonder how common "summed" traits are where a few to some are good to have while too many or too few is a bad thing. I heard of one computer example which by no means biologically proves anything apparently too high a learning rate caused some neural networks to start making increasingly bizzare associations and caused the convergence rate to plummet instead of improving past a certain point as spurious correlations resulted in incoherence. The schizophrenia thought disorder resemblance was explicitly noted.
  - barking 8y ago
    Also people with schizophrenia very probably have fewer children than average. So if it has a genetic component, it would be mainly their 'carrier' siblings who would pass on the trait to later generations.
notabee 8y ago
As we come to understand how much genetic expression is tied to environmental influences, such as with epigenetics silencing certain genes, all of these genetics/environment dichotomies are going to become less distinct. We need to talk about them as genetic susceptibility plus environmental trigger. For instance, say the environmental trigger is something extremely common, like the common cold. Even in carefully built twin studies there would be a high likelihood of the trigger occurring, which would make it appear heavily genetically caused, but the genes alone would not be sufficient to cause the condition.

AFAIK twin studies where babies were adopted suggest that schizophrenia is likely to be genetic in causation to a large degree. That doesn't rule out the common environment of the womb of course.

Nasrudith 8y ago

I thought the nazis proved that it /wasn't/ genetic strongly by murdering nearly every diagnosed schizophrenic under their domain. The rates were unchanged. Maternal nutrition seems far more likely given the prevalence being lowest in wealthier countries and higher in poorer countries on maps. Granted it may technically be epigenetic.

krageon 8y ago
All they proved is that murdering all people (that they could find) with schizophrenia doesn't lower the incidence rate of schizophrenia. This paper https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2800142/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2800142/ discusses a few of the reasons why that could be the case, but obviously it doesn't make grand claims.
- Nasrudith 8y ago
  Interesting that sufficient complexity may also work as a reason. I would have expected some deceease in a genetic context but I suppose sickle cell anemia is another example with simpler structuring given it is partially adaptive and partially maladaptive given one means malaria resistant blood and two means concave red cells bad at their job. Even if malaria vanished a thousand years ago the trait would probably stick around today. Thanks for the link and furthering my understanding. I wonder how common "summed" traits are where a few to some are good to have while too many or too few is a bad thing. I heard of one computer example which by no means biologically proves anything apparently too high a learning rate caused some neural networks to start making increasingly bizzare associations and caused the convergence rate to plummet instead of improving past a certain point as spurious correlations resulted in incoherence. The schizophrenia thought disorder resemblance was explicitly noted.
- barking 8y ago
  Also people with schizophrenia very probably have fewer children than average. So if it has a genetic component, it would be mainly their 'carrier' siblings who would pass on the trait to later generations.

notabee 8y ago

As we come to understand how much genetic expression is tied to environmental influences, such as with epigenetics silencing certain genes, all of these genetics/environment dichotomies are going to become less distinct. We need to talk about them as genetic susceptibility plus environmental trigger. For instance, say the environmental trigger is something extremely common, like the common cold. Even in carefully built twin studies there would be a high likelihood of the trigger occurring, which would make it appear heavily genetically caused, but the genes alone would not be sufficient to cause the condition.