While many animal species suffer from psychiatric symptoms, schizophrenia is specifically human. A new study has revealed that human speech and language play a role in the disease
led by Dr. Joel Dudley from Mount Sinai hospital in New York has shown that psychosis in humans may be due to the fact that our brains have evolved to be larger and more complex than those of non-human species.
Schizophrenia affects one percent of adults and can be potentially lethal. It is also known to be heavily
The study examined a segment of the human genome called human accelerated regions, or HAR's. HARs are short stretches of DNA that underwent fast evolution in humans when we split from chimpanzees. HARs often help regulate neighboring genes.
In order to determine whether there is a link between schizophrenia and HARs, Dudley and his team culled data from the Psychiatric Genomics Consortium, which had previously conducted a study identifying genetic variants associated with schizophrenia. They found that HARS play a role in regulating the genes associated with the disease.
The scientists then turned to gene expression profiles, which reveal where and when in the body certain genes are active. HAR-associated schizophrenia genes are found in areas of the genome that influence genes in the prefrontal cortex (PFC), a part of the brain involved in higher order thinking
. When the functions of the PFC are impaired, it is thought to contribute to psychosis.