QIMR Berghofer researchers have identified new links between seven regions on the human genome and specific symptoms of depression.
Senior study investigator and the head of QIMR Berghofer’s Translational Neurogenomics Group, Professor Eske Derks, said the findings improved understanding of the genetic architecture of depression.
About one in 11 people, or nine per cent of Australians, reported having depression or having depressed feelings in 2014-15, according to Australian Bureau of Statistics figures.
Patients are diagnosed with depression if they have at least five symptoms of the disorder including depressed mood and/or anhedonia, which is a loss of interest or pleasure in life.
The other symptoms include a change in appetite, sleep problems, fatigue, low self-esteem, concentration problems, psycho-motor changes and thoughts of self-harm.
Professor Derks said the study found there were unique genetic influences on most of those symptoms, explaining why patients with depression can present with a wide variety of clinical symptoms.
“Clinical depression is a complex and debilitating mental disorder and can be hard to treat because patients can present with varying symptoms despite all being clinically depressed,” Professor Derks said.
“Identifying that different symptoms have a slightly different genetic basis means doctors may be able to provide more personalised and precise interventions in the future.
“We identified for the first time three genetic regions related to sleep problems, two for anhedonia, one related to changes in appetite, and one for depressed mood.
“By knowing the genes that play a role in those symptoms, we may in the future be able to offer medications that target those genetic risk factors to patients experiencing the particular symptoms.
“This is another step towards personalised treatment for depression.
“When treating depression, we could argue that one size does not fit all. Some patients will respond better to treatment X, while other patients respond better to treatment Y, but patients still need to go through a trial and error stage since we cannot yet predict the most effective treatment for an individual patient.
“A better understanding of the role of specific symptoms may lead to more effective prediction of treatment response in the future.”
QIMR Berghofer student Jackson Thorp said the study examined genetic data and self-reported symptoms from 150,000 people from the UK Biobank.
“We used computational analyses to compare the symptoms with available genetic information from this large group,” he said.
“This study highlights the value of analysing the relationship between genes and specific symptoms to get a more accurate understanding of depression.”
The research findings have been published in the journal Psychological Medicine.
The research was supported by QIMR Berghofer.