Australian researchers have launched what they hope will be the world's biggest study of its kind into genetic causes of depression. The Australian Genetics of Depression Study is designed to detect genetic factors which contribute to clinical depression in hopes of developing better treatments and finding a cure.
When Leola Small suffered the trauma of a ruptured brain aneurism in her 20s, it triggered a less visible problem. In an interview with SBS she said:
"I started having feelings of darkness and lowness, I think. I can't really describe them any other way."
Ms Small was later diagnosed with clinical depression. She says she suspects her genetics may have made her susceptible.
"My mum is quite a high-strung person, doesn't deal with stress very well, gets very stressed all the time. My grandmother and my aunt on my dad's side, they too ... I think it's called, 'unrelenting standards, extraordinarily high achievers,' and that's what I've discovered that I am as well."
Researchers are seeking volunteers aged 18 and older currently being treated or treated in the past for clinical depression.
Volunteers would need to complete a 15-minute online survey and donate a saliva sample to be screened for hundreds of DNA variants. The process is known as a genome-wide association scan. That allows researchers to look for genetic similarities and differences, which would help find more personalised treatments.
Currently, people with clinical depression are often prescribed medication in the hope it will work and have few side effects. But its effectiveness is often not known until weeks later and, in many cases, is not successful.
Co-investigator Professor Ian Hickie, a mental-health campaigner from the University of Sydney's Brain and Mind Centre, says understanding what he calls depression's "genetic architecture" is critical.
"At the population level, we know about 30 per cent of the risk to depression is genetic, meaning the rest is environmental. What we don't know is, when someone comes to see us, or a family comes to see us, what the proportion is in their family and, more importantly, what sets of genes are really active in their family."
Researchers hope the study will lead to improved prevention and treatment. It is estimated up to one in seven Australians experiences clinical depression.
