A team of Canadian and Scottish scientists has pinpointed one of the genes that causes schizophrenia -- a breakthrough that sheds new light on how the disease can develop.
The work is to be published Thursday in the journal Neuron.
It demonstrates for the first time that schizophrenia can be caused by a malfunctioning gene, suggesting schizophrenia is linked to depression and bipolar disorder and may have the same underlying cause.
The discovery may someday help doctors identify which patients will respond to different types of treatments.
"I'm kind of excited about it and I think it should lead to lots of new things," Dr. John Roder, a senior investigator at Toronto's Mount Sinai Hospital, and the lead author of the paper told Â鶹´«Ã½net.
"I think in my mind this is the first valid animal model really that I would say represents the human disorder, and now rather than treating it with known drugs that work in humans, we can go through our libraries and chemical libraries for new structures and treat the mice and try to make them better, and then discover a new drug. That will take a few years, it won't be tomorrow."
Schizophrenia and bipolar affective disorder affect about one person in 50, worldwide.
Symptoms usually develop in late adolescence or early adulthood, and usually occur in families with a history of mental illness -- suggesting the diseases are linked to genetics.
Roder, who turned from his world-recognized cancer research to study the debilitating disease after his son was diagnosed with schizophrenia in 2001, says the findings may open the door to new treatments of schizophrenia, but it will likely be years before that actually happens.
Unlike cancer research, which is well funded and carries a high profile, mental health research is often underfunded and stigmatized, and progress is often slow.
Roder and experts from the University of Edinburgh and researchers from RIKEN in Japan, studied two types of damage to the gene DISC1.
The gene had already been linked to schizophrenia, bipolar disorder and depression through previous research in Edinburgh done with families that had a high incidence of mental illness.
They also found DISC1 was essential to brain signalling, and played a key role in learning, memory and mood.
The experts studied mice with two types of damage to the gene, and found that one responded to schizophrenia treatment known as antipsychotics, while the other responded well to anti-depressants, which are used to treat mood disorders.
"While the causes of schizophrenia, bipolar affective disorder and major depression are unknown, all the evidence points to subtle differences in the way the brain develops and to chemical changes in the brain. Our previous work identified the DISC1 gene as an important risk factor in these types of mental illness," said David Porteous, chair of Human Molecular Genetics and Medicine at the University of Edinburgh in a news release.
"By analyzing the behaviour of mice, we were able to provide further evidence of the importance of DISC1. We also found remarkable clear cut differences between the different types of damage to the gene and the treatment that was the most effective. By analyzing how the brain changes and develops over time we would hope that this would lead to more effective drugs to treat such illnesses."
