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Five new psychiatric diseases have overlapping patterns of genetic activity, according to a recent study

    Abdulaziz Sobh
    By Abdulaziz Sobh

    Categories: Health


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    Five new psychiatric diseases have overlapping patterns of genetic activity, according to a recent study

    Certain patterns of genetic activity appear to be common among five different psychiatric disorders: autism, schizophrenia, bipolar disorder, depression, and alcoholism, according to a new study. The document, which appears in the journal Science, was released on Thursday.
    The scientists analyzed data from 700 human brains, all donated from patients who suffered one of these major psychiatric disorders or from people who had not been diagnosed with mental illness. The scientists found similar levels of particular molecules in the brains of people with autism, schizophrenia and bipolar disorder; other similarities between bipolar depression and major depression; and other coincidences between major depression and alcoholism.
    "We are on the threshold of using genomics and molecular technology to examine [mental illness] in a way we have never been able to do before," said Daniel Geschwind, a neurogeneticist at the University of California, Los Angeles, who led the study. "Psychiatric disorders do not have an obvious pathology in the brain, but now we have the genomic tools to ask what is really wrong in these brains."
    These shared "signatures" related to the disease imply an interruption in the way that brain cells communicate with each other.
    "What we're seeing is giving us a sense of alterations in the way the neurons signal each other," Geschwind said. "We think some of that is a confusing activity, that's the next step to connect it to physiology: how these changes affect activation and neuronal connectivity, we have a clue that it's adding 'noise' to the system. they are attenuated or confused. "
    To eliminate the possibility that antipsychotic medication (which has probably been taken by many deceased mental patients) was causing patterns of superimposed molecules in the brain, the researchers compared the brain samples of their subjects with those taken from non-human primates that They were first given PCP to evoke psychosis, then treated with antipsychotic medications. The drugs seemed to partially "normalize" the disordered genetic activity in the brains of the monkey.
    "Genetic expression patterns may one day be good targets for the reversal of medication," said Geschwind. "In [our study] the drugs at least partially normalized gene expression in the brain."

    Many studies have identified variations in the genetic code that seem to be more common in people with psychiatric disorders. This approach goes a step further to show how genes are more or less active in the brains of people with diverse conditions. The study confirmed that genetic variations contributed to activity patterns in brains, but, as the authors wrote, "there is undoubtedly a contribution of environmental effects."
    Psychiatric disorders have some overlapping symptoms, which makes them difficult to diagnose. The molecular signatures in the new study suggest that schizophrenia, bipolar disorder, and autism have dysfunctional synapses, the points of contact between neurons where they exchange information. The brain support cells called microglia and astroglia had unusual activity patterns in some of the disorders, too.
    Geschwind credits not only the technological advances for the advance but also an extraordinary level of international collaboration made possible by the PsychEncode consortium of the National Institutes of Health, which encourages the exchange of information. The drop in the cost of sequencing the genetic code has also helped.
    What the research represents, said Geschwind, is the opportunity to approach molecularly targeted therapy, just like what is done with cancer. "This gives us the first roadmap of what is really going on with these disorders."