State’s genetic breakthrough on mental health
QUEENSLAND-led research has uncovered 70 new genes that contribute to people developing serious mental health disorders in a discovery scientists hope will eventually result in better drug treatments.
The research, led by QIMR Berghofer Medical Research Institute statistical geneticist Eske Derks, identified 46 previously unknown genes associated with schizophrenia, 11 linked to depression, eight to ADHD and five to bipolar disorder.
Professor Derks, who collaborated with researchers from Vanderbilt University in the US and the University of Amsterdam on the project, said the findings brought the number of genes known to contribute to the four mental health conditions to 331.
She said the researchers compared genetic data from tens of thousands of patients in four separate studies of schizophrenia, depression, ADHD and bipolar disorder with DNA from people without a history of mental illness.
They then used tissue from 700 deceased donors, who had never been diagnosed with a psychiatric illness, to study the expression of the 331 identified mental health genes in the brain, colon, adrenal gland and blood.
Prof Derks said this had given scientists a better understanding of whether the genes may be too active or not active enough in people with mental illness.
"This study provides more evidence about the genetic basis of these diseases and by better understanding the biology of the genes, attention can turn to finding the best drugs or treatments to manage them," she said.
"It's not enough that we know that gene X is involved in a disease, we need to know exactly what it is doing. Is it too active or not active enough and how do we change its level of activity to prevent or even stop symptoms."
The scientists' next step will be to find existing drugs that target key genes linked to schizophrenia in a bid to find better therapies for the severe mental illness.
"It's an approach called drug repurposing," Prof Derks explained. "We want to see if any existing drugs that have already been approved for human use can act on any of these genes or combination of genes.
"We need a wider range of drugs to treat these patients and I hope that this will provide the first clues for better treatment for mental health disease."
Prof Derks said she hoped to use the same research approach in future to better understand which genes were responsible for other psychiatric disorders such as obsessive compulsive disorder, substance abuse and eating disorders.
However, she stressed that severe mental health conditions were a complex interplay between genes and environmental triggers.
"It's possible that when you're born you may have a high genetic risk to develop a psychiatric disorder, but you don't develop any symptoms because you grow up in a very beneficial environment. Or, you may experience childhood trauma and that may trigger symptoms. It's what we call gene-environment interaction."